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Full text of "The Boy Mechanic: Volume 1: 700 Things for Boys to Do"

Project Gutenberg's The Boy Mechanic: Volume 1, by Popular Mechanics

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Title: The Boy Mechanic: Volume 1
       700 Things For Boys To Do

Author: Popular Mechanics

Release Date: June 18, 2004 [EBook #12655]

Language: English

Character set encoding: ISO-8859-1

*** START OF THIS PROJECT GUTENBERG EBOOK THE BOY MECHANIC: VOLUME 1 ***




Produced by Don Kostuch




The Boy Mechanic
Vol. 1
700 Things for Boys to Do
800 Illustrations Showing How



Jack Mansfield
+
Ed

Jan 28, 1938

August 1916

From Mother



THE BOY MECHANIC VOLUME I

Transcriber's Notes

This text accurately reproduces the original book except for
adherence to Project Gutenburg guidelines. Each project title is
followed by its original page number to allow use of the
alphabetical contents (index) at the end of the book. The book
used very complex typesetting to conserve space. This
transcription uses simple one-column linear layout.

The text only version is of limited use because of the widespread
occurrence of  diagrams and illustrations. Use the pdf version for
the complete text.

Many projects are of contemporary interest--magic, kites and
boomerangs for example. Try a "Querl" for starters.

There are many projects of purely historical interest, such as
chemical photography, phonographs, and devices for coal
furnaces.

Another class of projects illustrate the caviler attitude toward
environment and health in 1913. These projects involve items
such as gunpowder, acetylene, hydrogen, lead, mercury, sulfuric
acid, nitric acid, cadmium, potassium sulfate, potassium cyanide,
potassium ferrocyanide, copper sulfate, and hydrochloric acid.
Several involve the construction of hazardous electrical devices.
Please view these as snapshots of culture and attitude, not as
suggestions for contemporary activity.

Be careful and have fun or simply read and enjoy a trip into
yesterday.


[Illustration: How to Make a Glider (See page 171)]


THE BOY MECHANIC

VOLUME I

700 THINGS FOR BOYS TO DO

HOW TO CONSTRUCT

WIRELESS OUTFITS, BOATS, CAMP EQUIPMENT,
AERIAL GLIDERS, KITES, SELF-PROPELLED VEHICLES
ENGINES, MOTORS, ELECTRICAL APPARATUS, CAMERAS
AND
HUNDREDS OF OTHER THINGS WHICH DELIGHT EVERY BOY

WITH 800 ILLUSTRATIONS

COPYRIGHTED, 1913, BY H. H. WINDSOR CHICAGO
POPULAR MECHANICS CO.
PUBLISHERS



** A Model Steam Engine [1]

The accompanying sketch illustrates a two-cylinder single-acting,
poppet valve steam engine of home construction.

The entire engine, excepting the flywheel, shaft, valve cams,
pistons and bracing rods connecting the upper and lower plates of
the frame proper, is of brass, the other parts named being of cast
iron and bar steel.

The cylinders, G, are of seamless brass tubing, 1-1/2 in. outside
diameter; the pistons, H, are ordinary 1-1/2 in. pipe caps turned
to a plug fit, and ground into the cylinders with oil and emery.
This operation also finishes the inside of the cylinders.

The upright rods binding the top and bottom plates are of steel
rod about 1/8-in. in diameter, threaded into the top plate and
passing through holes in the bottom plate with hexagonal brass
nuts beneath.

The valves, C, and their seats, B, bored with a countersink bit,
are plainly shown. The valves were made by threading a copper
washer, 3/8 in. in diameter, and screwing it on the end of the
valve rod, then wiping on roughly a tapered mass of solder and
grinding it into the seats B with emery and oil.

The valve rods operate in guides, D, made of 1/4-in. brass tubing,
which passes through the top plate and into the heavy brass bar
containing the valve seats and steam passages at the top, into
which they are plug-fitted and soldered.

The location and arrangement of the valve seats and steam passages
are shown in the sketch, the flat bar containing them being
soldered to the top plate.

The steam chest, A, over the valve mechanism is constructed of

[Illustration: Engine Details]

1-in. square brass tubing, one side being sawed out and the open
ends fitted with pieces of 1/16 in. sheet brass and soldered. in.
The steam inlet is a gasoline pipe connection such as used on
automobiles.

The valve-operating cams, F, are made of the metal ends of an old
typewriter platen, one being finished to shape and then firmly
fastened face to face to the other, and used as a pattern in
filing the other to shape. Attachment to the shaft, N, is by means
of setscrews which pass through the sleeves.

The main bearings, M, on the supports, O, and the crank-end
bearings of the connecting rods, K, are split and held in position
by machine screws with provision for taking them up when worn.

The exhausting of spent steam is accomplished by means of slots,
I, sawed into the fronts of the cylinders at about 1/8 in. above
the lowest position of the piston's top at the end of the stroke,
at which position of the piston the valve rod drops into the
cutout portion of the cam and allows the valve to seat.

All the work on this engine, save turning the pistons, which was
done in a machine shop for a small sum, and making the flywheel,
this being taken from an old dismantled model, was accomplished
with a hacksaw, bench drill, carborundum wheel, files, taps and
dies. The base, Q, is made of a heavy piece of brass.

The action is smooth and the speed high. Steam is supplied by a
sheet brass boiler of about 3 pt. capacity, heated with a Bunsen
burner.
--Contributed by Harry F. Lowe, Washington, D. C.



** Magic Spirit Hand [2]

The magic hand made of wax is given to the audience for
examination, also a board which is suspended by four pieces of
common picture-frame wire. The hand is placed upon the board and
answers, by rapping, any question asked by members of the
audience. The hand and the board may be examined at any time and
yet the rapping can be continued, though surrounded by the
audience.

The Magic Wand, London, gives the secret of this spirit hand as
follows: The hand is prepared by concealing in the wrist a few
soft iron plates, the wrist being afterwards bound with black
velvet as shown in Fig. 1. The board is hollow, the top being made
of thin veneer (Fig. 2). A small magnet, A, is connected to a
small flat pocket lamp battery, B. The board is suspended by four
lengths of picture-frame wire one of which, E, is

[Illustration: Wax Hand on Board and Electrical Connections]

connected to the battery and another, D, to the magnet. The other
wires, F and G, are only holding wires. All the wires are fastened
to a small ornamental switch, H, which is fitted with a connecting
plug at the top. The plug can be taken out or put in as desired.

The top of the board must be made to open or slide off so that
when the battery is exhausted a new one can be installed.
Everything must be firmly fixed to the board and the hollow space
filled in with wax, which will make the board sound solid when
tapped.

In presenting the trick, the performer gives the hand and board
with wires and switch for examination, keeping the plug concealed
in his right hand. When receiving the board back, the plug is
secretly pushed into the switch, which is held in the right hand.
The hand is then placed on the board over the magnet. When the
performer wishes the hand to move he pushes the plug in, which
turns on the current and causes the magnet to attract the iron in
the wrist, and will, therefore, make the hand rap. The switch can
be made similar to an ordinary push button so the rapping may be
easily controlled without detection by the audience.




** Making Skis and Toboggans [3]

During the winter months everyone is thinking of skating, coasting
or ski running and jumping. Those too timid to run down a hill
standing upright on skis must take their pleasure in coasting or
skating.

The ordinary ski can be made into a coasting ski-toboggan by
joining two pairs together with bars without injury to their use
for running and jumping. The ordinary factory-made skis cost from
$2.50 per pair up, but any boy can make an excellent pair far 50
cents.

In making a pair of skis, select two strips of Norway pine free
from knots, 1 in. thick, 4 in. wide and 7 or 8 ft. long. Try to
procure as fine and straight a grain as possible. The pieces are
dressed thin at both ends leaving about 1 ft. in the center the
full thickness of 1 in., and gradually thinning to a scant 1/2 in.
at the ends. One end of each piece is tapered to a point beginning
12 in. from the end. A groove is cut on the under side, about 1/4
in. wide and 1/8 in. deep, and running almost the full length of
the ski. This will make it track straight and tends to prevent
side slipping. The shape of each piece for a ski, as it appears
before bending, is shown in Fig. 1.

The pointed end of each piece is placed in boiling water for at
least 1 hour, after which the pieces are ready for bending. The
bend is made on an ordinary stepladder. The pointed ends are stuck
under the back of one step and the other end securely tied to the
ladder, as shown in Fig. 2. They should remain tied to the ladder
48 hours in a moderate temperature, after which they will hold
their shape permanently.

The two straps, Fig. 3, are nailed an a little forward of the
center of gravity so that when the foot is lifted, the front

[Illustration: Fig. 1, Fig. 2, Fig. 3 -- Forming the Skis]

of the ski will be raised. Tack on a piece of sheepskin or deer
hide where the foot rests, Fig. 4.

The best finish for skis is boiled linseed oil. After two or three

[Illustration: Fig. 4 -- The Toe Straps]

applications the under side will take a polish like glass from the
contact with the snow.

The ski-toboggan is made by placing two pairs of skis together
side by side

[Illustration: Fig. 5 -- Ski-Toboggan]

and fastening them with two bars across the top. The bars are held
with V-shaped metal clips as shown in Fig. 5.
--Contributed by Frank Scobie, Sleepy Eye, Minn.



** Homemade Life Preserver [4]

Procure an inner tube of a bicycle tire, the closed-end kind, and
fold it in four alternate sections, as shown in Fig. 1. Cut or
tear a piece of cloth into strips about 1/2 in. wide, and knot
them together. Fasten this long strip of cloth to the folded tube
and weave it alternately in and out, having each

[Illustration: Fig. 1, Fig. 2; Inner Tube and Cover]

run of the cloth about 4 in. apart, until it is bound as shown in
Fig. 1.

Make a case of canvas that will snugly fit the folded tube when
inflated. The straps that hold the preserver to the body may be
made of old suspender straps. They are sewed to the case at one
end and fastened at the other with clasps such as used on overall
straps. The tube can be easily inflated by blowing into the valve,
at the same time holding the valve stem down with the teeth. The
finished preserver is shown in Fig. 2.



** How to Make Boomerangs [4]

When the ice is too thin for skating and the snow is not right for
skis, about the only thing to do is to stay in the house. A
boomerang club will help to fill in between and also furnishes
good exercise for the muscles of the arm. A boomerang can be made

[Illustration: Bending and Cutting the Wood]

of a piece of well seasoned hickory plank. The plank is well
steamed in a wash boiler or other large kettle and then bent to a
nice curve, as shown in Fig. 1. It is held in this curve until
dry, with two pieces nailed on the sides as shown.

After the piece is thoroughly dried out, remove the side pieces
and cut it into sections with a saw, as shown in Fig. 2. The
pieces are then dressed round. A piece of plank 12 in. wide and 2
ft. long will make six boomerangs.

To throw a boomerang, grasp it and hold the same as a club, with
the hollow side away from you. Practice first at some object about
25 ft. distant, and in a short time the thrower will be able to
hit the mark over 100 ft. away. Any worker in wood can turn out a
great number of boomerangs cheaply.
--Contributed by J. E. Noble, Toronto, Ontario.



** How to Make an Eskimo Snow House [5]
By GEORGE E. WALSH

Playing in the snow can be raised to a fine art if boys and girls
will build their creations with some attempt at architectural
skill and not content themselves with mere rough work. Working in
snow and ice opens a wide field for an expression of taste and
invention, but the construction of houses and forts out of this
plastic material provides the greatest amount of pleasure to the
normally healthy boy or girl.

The snow house of the Eskimo is probably the unhealthiest of
buildings made by any savage to live in, but it makes an excellent
playhouse in winter, and represents at the same time a most
ingenious employment of the arch system in building. The Eskimos
build their snow houses without the aid of any scaffolding or
interior false work, and while there is a keystone at the top of
the dome, it is not essential to the support of the walls. These
are self-supporting from the time the first snow blocks are put
down until the last course is laid.

The snow house is of the beehive shape and the ground plan is that
of a circle. The circle is first laid out on the ground and a
space cleared for it. Then a row of snow blocks is laid on the
ground and another course of similar blocks placed on top. The
snow blocks are not exactly square in shape, but about 12 in.
long, 6 in. high and 4 or 5 in. thick. Larger or smaller blocks
can be used, according to size of the house and thickness of the
walls.

First, the snow blocks must be packed and pressed firmly into
position out of moist snow that will pack. A very light, dry snow
will not pack easily, and it may be necessary to use a little
water. If the snow is of the right consistency, there will be no
trouble in packing and working with it. As most of the blocks are
to be of the same size throughout, it will pay to make a mold for
them by forming a box of old boards nailed together, minus the
top, and with a movable bottom, or rather no bottom at all. Place
the four sided box on a flat board and ram snow in it, forcing it
down closely. Then by lifting the box up and tapping the box from
above, the block will drop out. In this way blocks of uniform size
are formed, which makes the building simpler and easier.

While one boy makes the blocks another can shave them off at the
edges and two others can build the house, one inside of the circle
and the other outside. The Eskimos build their snow houses in this
way, and the man inside stays there until he is completely walled
in. Then the door and a window are cut through the wall.

[Illustration: Laying the Snow Bricks]

[Illustration: Three-Room Snow House]

Each layer of snow blocks must have a slight slant at the top
toward the center so that the walls will constantly curve inward.
This slant at the top is obtained better by slicing off the lower
surfaces of each block before putting it in its course. The top
will then have a uniform inward slant.

The first course of the snow house should be thicker than the
others, and the thickness of the walls gradually decreases toward
the top. A wall, however, made of 6-in. blocks throughout will
hold up a snow house perfectly, if its top is no more than 6 or 7
ft. above the ground. If a higher house is needed the walls should
be thicker at the base and well up toward the middle.

The builder has no mortar for binding the blocks together, and
therefore he must make his joints smooth and even and force in
loose snow to fill up the crevices. A little experience will
enable one to do this work well, and the construction of the house
will proceed rapidly. The Eskimos build additions to their houses
by adding various dome-shaped structures to one side, and the
young architect can imitate them. Such dome-shaped structures are
shown in one of the illustrations.

A fact not well understood and appreciated is that the Eskimo
beehive snow house represents true arch building. It requires no
scaffolding in building and it exerts no outward thrust. In the
ordinary keystone arch used by builders, a, temporary structure
must be erected to hold the walls up until the keystone is fitted
in position, and the base must be buttressed against an outward
thrust. The Eskimo does not have to consider these points. There
is no outward thrust, and the top keystone is not necessary to
hold the structure up. It is doubtful whether such an arch could
be built of brick or stone without scaffolding, but with the snow
blocks it is a simple matter.



** Secret Door Lock [6]

The sketch shows the construction of a lock I have on a door which
is quite a mystery to those who do not know how it operates. It
also keeps them out. The parts of the lock on the inside of the
door are shown in Fig. 1. These parts can be covered so that no
one can see them.

[Illustration: Fig. 1, Fig. 2, Fig. 3; The Lock Parts]

The ordinary latch and catch A are attached to the door in the
usual manner. The latch is lifted with a stick of wood B, which is
about 1 ft. long and 1 in. wide, and pivoted about two-thirds of
the way from the top as shown. The latch A is connected to the
stick B with a strong cord run through a staple to secure a
right-angle pull between the pieces. A nail, C, keeps the stick B
from falling over to the left. The piece of wood, D, is 6 or 8 in.
long and attached to a bolt that runs through the door, the
opposite end being fastened to the combination dial. Two kinds of
dials are shown in Fig. 2. The piece D is fastened on the bolt an
inch or two from the surface of the door to permit placing a
spiral spring of medium strength in between as shown in Fig. 3.
The opposite end of the bolt may be screwed into the dial, which
can be made of wood, or an old safe dial will do. A nail is driven
through the outer end of the piece D and the end cut off so that
it will pass over the piece B when the dial is turned. When the
dial is pulled out slightly and then turned toward the right, the
nail will catch on the piece B and open the latch. --Contributed
by Geo. Goodbrod, Union, Ore.



** A Convenient Hot-Dish Holder [7]

When taking hot dishes from the stove, it is very convenient to
have holders handy for use. For this purpose I screwed two screw
eyes into the ceiling, one in front of the stove directly above
the place where the holder should hang, and the other back of the
stove and out of the way. I next ran a strong cord through the two
eyes. To one end of the cord I attached a weight made of a clean
lump of coal. The cord is just long enough to let the weight hang
a few inches above the floor and pass through both screw eyes. I
fastened a small ring to the other end to keep the cord from
slipping back by the pull of the weight. I then fastened two
pieces of string to the ring at the end of the cord and attached
an iron holder to the end of each string. The strings should be
just long enough to keep the holders just over the stove where
they are always

[Illustration: Holders in a Convenient Place]

ready for use, as the weight always draws them back to place.
--Contributed by R. S. Merrill, Syracuse, New York.



** Magic-Box Escape [7]

The things required to make this trick are a heavy packing box
with cover, one pair of special hinges, one or two hasps for as
many padlocks and a small buttonhook, says the Sphinx.

The hinges must be the kind for attaching inside of the box. If
ordinary butts are used, the cover of the box

[Illustration: Box with Hinges and Lock]

must be cut as much short as the thickness of the end board. The
hinges should have pins that will slip easily through the parts.

Before entering the box the performer conceals the buttonhook on
his person, and as soon as the cover is closed and locked, and the
box placed in a cabinet or behind a screen, he pushes the pin or
bolt of the hinge out far enough to engage the knob end with the
buttonhook which is used to pull the pin from the hinge. Both
hinges are treated in this manner and the cover pushed up,
allowing the performer to get out and unlock the padlocks with a
duplicate key. The bolts are replaced in the hinges, the box
locked and the performer steps out in view.



** A Flour Sifter [7]

When sifting flour in an ordinary sieve I hasten the process and
avoid the disagreeable necessity of keeping my hands in the flour
by taking the top from a small tin lard can and placing it on top
of the flour with its sharp edges down. When the sieve is shaken,
the can top will round up the flour and press it through quickly.
--Contributed by L. Alberta Norrell, Augusta, Ga.



** A Funnel [7]

An automobile horn with the bulb and reed detached makes a good
funnel. It must be thoroughly cleaned and dried after using as a
funnel.



** How to Make Comer Pieces for a Blotter Pad [8]

To protect the corners of blotting pads such as will be found on
almost every writing desk, proceed as follows:

First, make a design of a size proportionate to the size of the
pad and make a right-angled triangle, as shown in Fig. 1, on
drawing paper. Leave a small margin all around the edge and then
place some decorative form therein. Make allowance for flaps on
two sides, as shown, which may later be turned back and folded
under when the metal is worked. It should be noted that the
corners of the design are to be clipped slightly. Also note the
slight overrun at the top with the resulting V-shaped indentation.

To make a design similar to the one shown, draw one-half of it,
then fold along the center line and rub the back of the paper with
a knife handle or some other hard, smooth surface, and the other
half of the design will be traced on the second side. With the
metal shears, cut out four pieces of copper or brass of No. 22
gauge and with carbon paper trace the shape and decorative design
on the metal. Then cut out the outline and file the edges smooth.

Cover the metal over with two coats of black asphaltum varnish,
allowing each coat time to dry. Cover the back and all the face
except the white background. Immerse in a solution of 3 parts
water, 1 part nitric acid and 1 part sulphuric acid. When the
metal has been etched to the desired depth, about 1-32 of an inch,
remove it and clean off the asphaltum with turpentine. Use a stick
with a rag tied on the end for this purpose so as to keep the
solution off the hands and clothes. The four pieces should be
worked at the same time, one for each corner.

It remains to bend the flaps. Place the piece in a vise, as shown
in Fig. 2, and bend the flap sharply to a right angle. Next place
a piece of metal of a thickness equal to that of the blotter pad
at the bend and with the mallet bring the flap down parallel to
the face of the corner piece, Fig. 3. If the measuring has been
done properly, the flaps

[Illustration: Manner of Forming the Plates]

ought to meet snugly at the corner. If they do not, it may be
necessary to bend them back and either remove some metal with the
shears or to work the metal over farther. All the edges should be
left smooth, a metal file and emery paper being used for this
purpose.

If a touch of color is desired, it may be had by filling the
etched parts with enamel tinted by the addition of oil colors,
such as are used for enameling bathtubs. After this has dried,
smooth it off with pumice stone and water. To keep the metal from
tarnishing, cover it with banana-oil lacquer.



** Boring Holes in Cork [8]

The following hints will be found useful when boring holes in
cork. In boring through rubber corks, a little household ammonia
applied to the bit enables one to make a much smoother hole and
one that is nearly the same size at both openings. The common
cork, if rolled under the shoe sole, can be punctured easily and a
hole can be bored straighter. The boring is made easier by boiling
the cork, and this operation insures a hole that will he the
desired size and remain the size of the punch or bit used.



** Self-Lighting Arc Searchlight [9]

A practical and easily constructed self-lighting arc searchlight
can be made in the following manner: Procure a large can, about 6
in. in diameter, and cut three holes in its side about 2 in. from
the back end, and in the positions shown in the sketch. Two of the
holes are cut large enough to hold a short section of a garden
hose tightly, as shown at AA. A piece of porcelain tube, B, used
for insulation, is fitted tightly in the third hole. The hose
insulation A should hold the carbon F rigidly, while the carbon E
should rest loosely in its insulation.

The inner end of the carbon E is supported by a piece of No. 25
German-silver wire, C, which is about 6 in. long. This wire runs
through the

[Illustration: Arc in a Large Can]

porcelain tube to the binding post D. The binding post is fastened
to a wood plug in the end of the tube. The tube B is adjusted so
that the end of the carbon E is pressing against the carbon F. The
electric wires are connected to the carbon F and the binding post
D. A resistance, R, should be in the line.

The current, in passing through the lamp, heats the strip of
German-silver wire, causing it to expand. This expansion lowers
the end of the carbon E, separating the points of the two carbons
and thus providing a space between them for the formation of an
arc. When the current is turned off, the German-silver wire
contracts and draws the two carbon ends together ready for
lighting again. The feed can be adjusted by sliding the carbon F
through its insulation.

A resistance for the arc may be made by running the current
through a water rheostat or through 15 ft. of No. 25 gauge
German-silver wire.
--Contributed by R. H. Galbreath, Denver, Colo.



** A Traveler's Shaving Mug [9]

Take an ordinary collapsible drinking cup and place a cake of
shaving soap in the bottom ring. This will provide a shaving mug
always ready for the traveler and one that will occupy very little
space in the grip.



** Homemade Snowshoes [9]

Secure four light barrel staves and sandpaper the outside smooth.
Take two old shoes that are extra large and cut off the tops and
heels so as to leave only the toe covering fastened to the sole.
Purchase two long book straps, cut them in two in the middle and
fasten the ends on the toe covering, as shown in Fig. 1. The
straps are used to attach the snowshoe to the regular shoe. When
buckling up the straps be sure to leave them loose enough for the
foot to work freely, Fig. 2. Fasten the barrel staves in pairs,
leaving a space of 4 in. between them as shown in Fig. 3, with
thin strips of wood. Nail the old shoe soles to crosspieces

[Illustration: Made from Barrel Staves]

placed one-third of the way from one end as shown. --Contributed
by David Brown, Kansas City, Mo.



** Fish Signal for Fishing through Ice [10]

Watching a fish line set in a hole cut in the ice on a cold day is
very disagreeable, and the usual method is to

[Illustration: Bell and Battery in a Box]

have some kind of a device to signal the fisherman when a fish is
hooked. The "tip ups" and the "jumping jacks" serve their purpose
nicely, but a more elaborate device is the electric signal. A
complete electric outfit can be installed in a box and carried as
conveniently as tackle.

An ordinary electric bell, A, Fig. 1, having a gong 2-1/2 in. in
diameter, and a pocket battery, B are mounted on the bottom of the
box. The electric connection to the bell is plainly shown. Two
strips of brass, C, are mounted on the outside of the box. The
brass strips are shaped in such a way as to form a circuit when
the ends are pulled together. The box is opened and set on the ice
near the fishing hole. The fish line is hung over a round stick
placed across the hole and then tied to the inside strip of brass.
When the fish is hooked the line will pull the brass points into
contact and close the electric circuit.



** Homemade Floor Polisher [10]

A floor polisher is something that one does not use but two or
three times a year. Manufactured polishers come in two sizes, one
weighing 15 lb., which is the right weight for family use, and one
weighing 25 lb.

A polisher can be made at home that will do the work just as well.
Procure a wooden box such as cocoa tins or starch packages are
shipped in and stretch several thicknesses of flannel or carpet
over the bottom, allowing the edges to extend well up the sides,
and tack smoothly. Make a handle of two stout strips of wood, 36
in. long, by joining their upper ends to a shorter crosspiece and
nail it to the box. Place three paving bricks inside of the box,
and the polisher will weigh about 16 lb., just the right weight
for a woman to use. The polisher is used by rubbing with the grain
of the wood.
--Contributed by Katharine D. Morse, Syracuse, N. Y.



** Tying Paper Bag to Make a Carrying Handle [10]

In tying the ordinary paper bag, the string can be placed in the
paper in such a way that it will form a handle to carry the
package, and also prevent any leakage of the contents. The bag
must be long enough for the end to fold over as shown in Fig. 1.
The folds are made over the string, as in

[Illustration: Stages in Tying a Bag]

Fig. 2. The string is then tied, Fig. 3, to form a handle, Fig. 4.
--Contributed by James M. Kane, Doylestown, Pa.



** Equilibrator for Model Aeroplanes [11]

On one of my model aeroplanes I placed an equilibrator to keep it
balanced. The device was attached to a crosspiece fastened just
below the propeller between the main frame uprights. A stick was
made to swing on a bolt in the center of the crosspiece to which
was attached a weight at the lower end and two lines connecting
the ends of the planes at the upper end. These are shown in Fig.
1. When the aeroplane tips, as

[Illustration: Warping the Aeroplane Wings]

shown in Fig. 2, the weight draws the lines to warp the plane so
it will right itself automatically.
--Contributed by Louis J. Day, Floral Park, N. Y.



** Repairing Christmas-Tree Decorations [11]

Small glass ornaments for Christmas tree decorations are very
easily broken on the line shown in the sketch. These can be easily
repaired by inserting in the neck a piece of match, toothpick or
splinter of wood and tying the hanging string to it.

[Illustration: Repaired Decoration]



** Homemade Scroll Saw [11]

A scroll saw, if once used, becomes indispensable in any home
carpenter chest, yet it is safe to say that not one in ten
contains it. A scroll saw is much more useful than a keyhole saw
for sawing small and irregular holes, and many fancy knick-knacks,
such as brackets, bookracks and shelves can be made with one.

A simple yet serviceable scroll saw frame can be made from a piece
of cold-rolled steel rod, 3/32 or 1/4 in. in diameter, two 1/8-in.
machine screws, four washers and four square nuts. The rod should
be 36 or 38 in. long, bent as shown in Fig. 1. Place one washer on
each screw and put the screws through the eyelets, AA, then place
other washers on and fasten in place by screwing one nut on each
screw, clamping the washers against the frame as tightly as
possible. The saw, which can be purchased at a local hardware
store, is fastened between the clamping nut and another nut as
shown in Fig. 2.

[Illustration: Frame Made of a Rod]

If two wing nuts having the same number and size of threads are
available, use them in place of the outside nuts. They are easier
to turn when inserting a saw blade in a hole or when removing
broken blades.
--Contributed by W. A. Scranton, Detroit, Michigan.



** How to Make a Watch Fob [12]

The fixtures for the watch fob shown--half size--may be made of
either brass, copper, or silver. Silver is the most desirable but,
of course, the most expensive. The buckle is to be purchased. The
connection is to be of leather of a color to harmonize with that
of the fixtures. The body of the fob may be of leather of suitable
color or of silk. Of the leathers, green and browns are the most
popular, though almost any color may be obtained.

Make full size drawings of the outline and design of the fixtures.
With carbon paper trace these on the metal. Pierce the metal of
the parts that are to be removed with a small hand drill to make a
place for the leather or silk. With a small metal saw cut out
these parts and smooth up the edges, rounding them slightly so
they will not cut the leather or silk. Next cut out the outlines
with the metal shears. File these edges, rounding and smoothing
with emery paper. The best way of handling the decorative design
is to etch it and, if copper or brass, treat it with color.

For etching, first cover the metal with black asphaltum varnish,
on the back and all the parts that are not to be touched with the
acid. In the design shown, the unshaded parts should not be etched
and should, therefore, be covered the same as the back. Apply two
coats, allowing each time to dry, after which immerse the metal in
a solution prepared as follows: 3 parts water, 1 part nitric acid,
1 part sulphuric acid. Allow the metal to remain in this until the
acid has eaten to a depth of 1/32 in., then remove it and clean in
a turpentine bath, using a swab and an old stiff brush. The amount
of time required to do the etching will depend upon the strength
of the liquid, as well as the depth of etching desired.

[Illustration: Watch Fob]

For coloring silver, as well as brass and copper, cover the metal
with a solution of the following: 1/2 pt. of water in which
dissolve, after breaking up, five cents worth of sulphureted
potassium. Put a teaspoonful of this into a tin with 2 qt. of
water. Polish a piece of scrap metal and dip it in the solution.
If it colors the metal red, it has the correct strength. Drying
will cause this to change to purple. Rub off the highlights,
leaving them the natural color of the metal and apply a coat of
banana-oil lacquer.



** An Austrian Top [12]

All parts of the top are of wood and they are simple to make. The
handle is a piece of pine, 5-1/4 in. long, 1-1/4 in. wide and 3/4
in. thick. A handle, 3/4 in. in diameter, is formed on one end,
allowing only 1-1/4 in. of the other end to remain rectangular in
shape. Bore a 3/4-in. hole in this end for the top. A 1/16-in.
hole is bored in the edge to enter the large hole as shown. The
top can be cut from a broom handle or a round stick of hardwood.

[Illustration: Parts of the Top]

To spin the top, take a piece of stout cord about 2 ft. long, pass
one end through the 1/16-in. hole and wind it on the small part of
the top in the usual way, starting at the bottom and winding
upward. When the shank is covered, set the top in the 3/4-in.
hole. Take hold of the handle with the left hand and the end of
the cord with the right hand, give a good quick pull on the cord
and the top will jump clear of the handle and spin vigorously.
--Contributed by J.F. Tholl, Ypsilanti, Michigan.



** Pockets for Spools of Thread [13]

A detachable pocket for holding thread when sewing is shown
herewith. The dimensions may be varied to admit any number or size
of spools. Each pocket is made to take a certain size spool, the
end of the thread being run through the cloth front for obtaining
the length for threading a needle. This will keep the thread from
becoming tangled and enable it always to be readily drawn out to
the required length.
--Contributed by Miss L. Alberta Norrell, Augusta, Ga.

[Illustration: Pockets for Thread]



** Cleaning Leather on Furniture [13]

Beat up the whites of three eggs carefully and use a piece of
flannel to rub it well into the leather which will become clean
and lustrous. For black leathers, some lampblack may be added and
the mixture applied in the same way.



** A Baking Pan [13]

When making cookies, tarts or similar pastry, the housewife often
wishes for something by which to lift the baked articles from the
pan. The baking tray or pan shown in the sketch not only protects
the hands from burns but allows the baked articles easily to slip
from its surface. The pan is made from a piece of sheet iron
slightly larger than the baking space desired. Each end of the
metal is cut so that a part may be turned up and into a roll to
make handles for the pan.

[Illustration: Baking Pan without Sides]

A wire or small rod is placed between the handles as shown. This
wire is fastened at each end and a loop made in the center. The
pan can be removed from the oven by placing a stick through the
loop and lifting it out without placing the hands inside the hot
oven. The baking surface, having no sides, permits the baked
articles to be slid off at each side with a knife or fork. --A. A.
Houghton, Northville, Mich.



** A Broom Holder [13]

[Illustration: Broom Holder]

A very simple and effective device for holding a broom when it is
not in use is shown in the sketch. It is made of heavy wire and
fastened to the wall with two screw eyes, the eyes forming
bearings for the wire. The small turn on the end of the straight
part is to hold the hook out far enough from the wall to make it
easy to place the broom in the hook. The weight of the broom keeps
it in position.
--Contributed by Irl Hicks, Centralia, Mo.



**Stringing Wires [13]

A string for drawing electric wires into bent fixtures can be
easily inserted by rolling it into a small ball and blowing it
through while holding one end.



** A Darkroom Lantern [14]

Procure an ordinary 2-qt. glass fruit jar, break out the porcelain
lining in the cover and cut a hole through the metal, just large
enough to fit over the socket of an incandescent electric globe,
then solder cover and socket together, says Studio Light. Line the
inside of the jar with two thicknesses of good orange post office
paper. The best lamp for the purpose is an 8-candlepower showcase
lamp, the same as shown in the illustration. Screw the lamp into
the socket and screw the cover onto the jar, and you have a safe
light of excellent illuminating power.

When you desire to work by white light, two turns will remove the
jar.

[Illustration: Darkroom Lantern]

If developing papers are being worked, obtain a second jar and
line with light orange paper, screw into the cover fastened to the
lamp and you have a safe and pleasant light for loading and
development. By attaching sufficient cord to the lamp, it can be
moved to any part of the darkroom, and you have three lamps at a
trifling cost.



** Preventing Vegetables from Burning in a Pot [14]

Many housekeepers do not know that there is a simple way to
prevent potatoes from burning and sticking to the bottom of the
pot. An inverted pie pan placed in the bottom of the pot avoids
scorching potatoes. The water and empty space beneath the pan
saves the potatoes. This also makes the work of cleaning pots
easier as no adhering parts of potatoes are left to be scoured
out.



** A Clothes Rack [14]

A clothes-drying rack that has many good features can be made as
shown in the illustration. When the rack is

[Illustration: Folding Clothes Rack]

closed it will fit into a very small space and one or more wings
can be used at a time as the occasion or space permits, and not
tip over. The rack can be made of any hard wood and the material
list is as follows:

1 Center post. 1-1/4 in. square by 62 in. 4 Braces. 1-1/4 in.
square by 12 in. 16 Horizontal bars. 1 by 1-1/4 by 24 in. 4
Vertical pieces. 1/4 by 1 by 65 in.

Attach the four braces for the feet with finishing nails after
applying a good coat of glue.

The horizontal bars are fastened to the vertical pieces with
rivets using washers on both sides. The holes are bored a little
large so as to make a slightly loose joint. The other ends of the
bars are fastened to the center post with round head screws. They
are fastened, as shown in the cross-section sketch, so it can be
folded up.
--Contributed by Herman Fosel, Janesville, Wis.



** Homemade Shower Bath [15]

[Illustration: A Shower Bath That Costs Less Than One Dollar to
Make]

While in the country during vacation time, I missed my daily bath
and devised a shower bath that gave complete satisfaction. The
back porch was enclosed with sheeting for the room, and the
apparatus consisted of a galvanized-iron pail with a short nipple
soldered in the center of the bottom and fitted with a valve and
sprinkler. The whole, after filling the pail with water, was
raised above one's head with a rope run over a pulley fastened to
the roof of the porch, and a tub was used on the floor to catch
the water. A knot should be tied in the rope at the right place,
to keep it from running out of the pulley while the pail is
lowered to be filled with water, and a loop made in the end, which
is placed over a screw hook turned into the wall. If the loop is
tied at the proper place, the pail will be raised to the right
height for the person taking the shower bath.

The water will run from 10 to 15 minutes. The addition of some hot
water will make a splendid shower bath.
--Contributed by Dr. C. H. Rosenthal, Cincinnati, O.



** How to Make Small Sprocket Wheels [15]

As I needed several small sprocket wheels and had none on hand, I
made them quickly without other expense than the time required,
from scrap material. Several old hubs with the proper size bore
were secured. These were put on an arbor and turned to the size of
the bottom of the teeth. Hole were drilled and tapped to
correspond to the number of teeth required and old stud bolts
turned into them. The wheels were again placed on the arbor and
the studs turned to the required size. After rounding the ends of
the studs, the sprockets were ready for use and gave perfect
satisfaction.
--Contributed by Charles Stem, Phillipsburg, New York.



** Pot-Cover Closet [16]

The sides of the cover closet are cut as shown in Fig. 1 and
shelves are nailed between them at a slight angle.

[Illustration: FIG. 1  FIG. 2  Closet for Holding Pot Covers]

No dimensions are given as the space and the sizes of the covers
are not always the same. The back is covered with thin boards
placed vertically. The front can be covered with a curtain or a
paneled door as shown.
--Contributed by Gilbert A. Wehr, Baltimore, Md.



** Aid in Mixing Salad Dressing [16]

Some cooks find it a very difficult matter to prepare salad
dressing, principally mayonnaise dressing, as the constant
stirring and pouring of oil and liquids are required in the
operation. The simple homemade device shown in the accompanying
sketch greatly assists

[Illustration: Bottle in Stand]

in this work. It consists of a stand to hold a bottle, the mouth
of which rests against a. small gate directly in the rear of the
attached tin trough. The weight of the bottle and the contents
against the gate serves as a check or stopper. If the gate is
raised slightly, it will permit a continuous flow of liquid of the
desired amount.



** Saving Overexposed Developing Prints [16]

In using developing papers, either for contact printing or
enlargements, you are, by all rules of the game, entitled to a
certain number of overexposed prints, says a correspondent of
Camera Craft. But there is no reason why you should lose either
the paper or the time and trouble expended in making these prints.
By using the following method, you can turn these very dark prints
into good ones.

First: these overexposed prints must be fully developed. Do not
try to save them by rushing them out of the developer into the
short-stop or fixing bath. The results will be poor, and, if you
try to tone them afterward, the color will be an undesirable,
sickly one. Develop them into strong prints, thoroughly fix, and
wash until you are sure all hypo is removed. In my own practice, I
carry out this part of the work thoroughly, then dry the prints
and lay aside these dark ones until there is an accumulation of a
dozen or more, doing this to avoid too frequent use of the very
poisonous bleaching solution. The bleacher is made up as follows
and should be plainly marked "Poison."

    Cyanide of potassium ....... 2 oz.
    Iodide of potassium ....... 20 gr.
    Water ..................... 16 oz.

Place the dry print, without previous wetting, in this solution.
It will bleach slowly and evenly, but, when it starts to bleach,
transfer it to a tray of water, where it will continue to bleach.
When the desired reduction has taken place, stop the action at
once by immersing the print in a 10-per-cent solution of borax.
The prints may be allowed to remain in this last solution until
they are finished. A good final washing completes the process.
This washing must be thorough and a sponge or a tuft of cotton
used to clean the surface of the print.

With a little practice, this method of saving prints that are too
dark becomes easy and certain. The prints are lightened and at the
same time improved in tone, being made blue-black with a delicate
and pleasing quality that will tempt you to purposely overexpose
some of your prints in order to tone them by this method for
certain effects. The process is particularly valuable to the
worker in large sizes, as it provides a means of making quite a
saving of paper that would otherwise be thrown away.



** An Ironing-Board Stand [17]

An ordinary ironing board is cut square on the large end and a
slot cut 1-1/2 in. wide and 4 in. long to admit the angle support.
The support is placed against the table and the board

[Illustration: Stand Attached to Table]

is pressed down against the outer notch which jams against the
table, thus holding the board rigid and in such a position as to
give free access for ironing dresses, etc.
--Contributed by T. L. Gray, San Francisco, Cal.



** A Desk Blotting Pad [17]

Procure four sheets of blotting paper, preferably the colored
kind, as it will appear clean much longer than the white. The size
of the pad depends on the size of the blotting paper.

Fold four pieces of ordinary wrapping paper, 5 by 15 in. in size,
three times, to make it 5 by 5 in. Fold each one from corner to
corner as shown in Fig. 1 and again as in Fig. 2. Paste the last
fold together and the corner holders are complete. Put one on each
corner of the blotting paper. They can be fastened with a small
brass paper fastener put through the top of the holder. The
blotting paper can

[Illustration: Fig. 1, 2, 3 Paper Corners for Blotter Pads]

be easily changed by removing the holders and fasteners. Corners
complete are shown in Fig. 3.
--Contributed by J. Wilson Aldred Toronto, Canada.



** Sleeve Holders for Lavatories [17]

A very handy article is an attachment on wash basins or lavatories
for holding the sleeves back while washing the hands. It is very
annoying to have the sleeves continually slip down and become wet
or soiled. The simple device shown herewith can be made with bent
wires or hooks and attached in such a way that it can be dropped
out

[Illustration: Wires Attached to a Lavatory]

of the way when not in use.
--Contributed by L.J. Monahan, Oshkosh, Wisconsin.



** Removing Tarnish [17]

A pencil eraser will remove the tarnish from nickel plate, and the
ink eraser will remove the rust from drawing instruments.



** How to Make a Brass Bookmark [18]

Secure a piece of brass of No. 20 gauge, having a width of 2-1/4
in. and a length of 5 in. Make a design similar to that shown, the
head of which is 2 in. wide, the shaft 1 in. wide below the

[Illustration: FIG. 1 Fig. 2 The Pattern and the Finished
Bookmark]

head and the extreme length 4-1/2 in. Make one-half of the design,
as shown in Fig. 1, freehand, then trace the other half in the
usual way, after folding along the center line. Trace the design
on the metal, using carbon paper, which gives the outline of the
design Fig. 2.

With the metal shears, cut out the outline as indicated by the
drawing. With files, smooth off any roughness

[Illustration: Drilling and Sawing the Metal]

and form the edge so that it shall be nicely rounded.

The parts of the design in heavy color may be treated in several
ways. A very satisfactory treatment is obtained by etching, then
coloring. Clean the metal thoroughly with pumice stone and water
or with alcohol before the design is applied. Cover all the metal
that is not to be lowered with a thick coating of asphaltum. Allow
this to dry, then put on a second coat. After this has dried,
thoroughly immerse the metal in a solution composed as follows: 3
parts water, 1 part sulphuric acid, 1 part nitric acid.

Allow the metal to remain in this solution until the exposed part
has been eaten about 1/32 in. deep, then remove it and clean off
the asphaltum, using turpentine. Do not put the hands in the
solution, but use a swab on a stick.

For coloring olive green, use 2 parts water to 1 part permuriate
of iron. Apply with a small brush.

The lines at A and B will need to be cut, using a small metal saw.
Pierce a hole with a small drill, Fig. 3, large enough to receive
the saw and cut along the lines as in Fig. 4. A piece of wood with
a V-shaped notch which is fastened firmly to the bench forms the
best place in which to do such sawing. The teeth of the saw should
be so placed that the sawing will be done on the downward stroke.
The metal must be held firmly, and the saw allowed time to make
its cut, being held perpendicular to the work.

After the sawing, smooth the edges of the metal with a small file
and emery paper. The metal clip may be bent outward to do this
part of the work.



** Cheesebox-Cover Tea Tray [18]

The cover from a cheesebox can be converted into a tea tray that
is very dainty for the piazza, or for serving an invalid's
breakfast.

First sandpaper the wood until it is smooth, then stain it a
mahogany color. The mahogany stain can be obtained ready prepared.
After the stain has dried, attach brass handles, which can be
obtained for a small sum at an upholsterer's shop. A round
embroidered doily in the bottom adds to the appearance of the
tray.
--Contributed by Katharine D. Morse, Syracuse, New York.



** Piercing-Punch for Brass [19]

Drill a 1/2-in. hole through a block of pine or other soft wood 2
in. thick. Tack over one end of the hole a piece of pasteboard in
which seven coarse sewing-machine needles have been inserted. The
needles should be close together and pushed through the pasteboard
until the points show. The hole is then filled with melted babbitt
metal. When this is cold, the block is split and the pasteboard
removed. This tool makes neat pierced work and in making brass
shades, it does the work rapidly.
--Contributed by H. Carl Cramer, East Hartford, Conn.



** Kitchen Chopping Board [19]

Cooks can slice, chop or mince vegetables and various other food
rapidly by placing the little device, as shown, on a chopping
board. Ii is an ordinary staple, driven in just far enough to
allow a space for the end of an ordinary pointed kitchen knife to
fit in it. The staple is driven in the edge of the chopping board.
The knife can be raised and lowered with one hand, as

[Illustration: Knife Attached to the Board]

the material is passed under the blade with the other. Great
pressure can be applied and the knife will not slip. --Contributed
by M. M. Burnett, Richmond, Cal.



** Carrying Mattresses [19]

Sew straps to the sides of mattresses and they can be handled much
easier.



** A Carpenter's Gauge [19]

The home workshop can be supplied with a carpenter's gauge without
any expense by the use of a large spool and

[Illustration: Round Stick In a Spool]

a round stick of wood. The stick should be dressed to fit the hole
in the spool snugly and a small brad driven through one end so
that the point will protrude about 1/16 in.

The adjustment of the gauge is secured by driving the stick in the
hole in the direction desired. A better way and one that will make
the adjusting easy is to file the point end of a screw eye flat
and use it as a set screw through a hole in the side of the spool.



** A Flatiron Rest [19]

The iron rest and wall hanger shown in the sketch is made of sheet
iron. The upturned edges of the metal are

[Illustration: Board or Wall Iron Rest]

bent to fit the sloping sides of the iron. The holder and iron can
be moved at the same time.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Use for Paper Bags [19]

When groceries are delivered, save the paper bags and use them for
staring bread and cakes. Tie the neck of the bag with a string and
it will keep the contents fresh and clean.
--Contributed by Mrs. L. H. Atwell, Kissimmee, Florida.



** Use Chalk on Files [19]

If a little chalk is rubbed on a file before filing steel, it will
keep the chips from sticking in the cuts on the file and
scratching the work.



** A Homemade Steam Turbine [20]
By WILLIAM H. WARNECKE

Procure some brass, about 3/16 in. thick and 4 in. square; 53
steel pens, not over 1/4 in. in width at the shank; two enameled,
or tin, saucers or pans, having a diameter on the inside part of
about 4-1/2 in.; two stopcocks with 1/8 in. holes; one shaft; some
pieces of

[Illustration: Details of Turbine]

brass, 1/4 in. thick, and several 1/8-in. machine screws.

Lay out two circles on the 3/16-in. brass, one having a diameter
of 3-1/2 in. and the other with a diameter of 2-3/4 in. The
outside circle is the size of the finished brass wheel, while the
inside circle indicates the depth to which the slots are to be
cut. Mark the point where a hole is to be drilled for the shaft,
also locate the drill holes, as shown at A, Fig. 1. After the
shaft hole and the holes A are drilled in the disk, it can be used
as template for drilling the side plates C.

The rim of the disk is divided into 53 equal parts and radial
lines drawn from rim to line B, indicating the depth of the slots.
Slots are cut in the disk with a hacksaw on the radial lines. A
small vise is convenient for holding the disk while cutting the
slots.

When cutting the disk out of the rough brass, sufficient margin
should be left for filing to the true line. The slots should be
left in their rough state as they have a better hold on the pens
which are used for the blades. The pens are inserted in the slots
and made quite secure by forcing ordinary pins on the inside of
the pens and breaking them off at the rim, as shown in Fig. 4.

When the pens are all fastened two pieces of metal are provided,
each about 1 in. in diameter and 1/32 in. thick, with a 3/8-in.
hole in the center, for filling pieces which are first placed
around the shaft hole between the disk and side plates C, Fig. 1.
The side plates are then secured with some of the 1/8-in. machine
screws, using two nuts on each screw. The nuts should be on the
side opposite the inlet valves. The shaft hole may also be filed
square, a square shaft used, and the ends filed round for the
bearings.

The casing for the disk is made of two enameled-iron saucers, Fig.
2, bolted together with a thin piece of asbestos between them to
make a tight joint. A 3/4-in. hole is cut near the edge of one of
the saucers for the exhaust. If it is desired to carry the exhaust
beyond the casing, a thin pipe can be inserted 1/4 in. into the
hole. Holes are drilled through the pipe on both inside and
outside of the casing, and pins inserted, as shown in Fig. 5.
Solder is run around the outside pin to keep the steam from
escaping. At the lowest point of the saucer or casing a 1/8-in.
hole is drilled to run off the water. A wood plug will answer for
a stopcock.

If metal dishes, shaped from thick material with a good coating of
tin, can be procured, it will be much easier to construct the
casing than if enameled ware is used. The holes can be easily
drilled and the parts fitted together closely. All seams and
surfaces around fittings can be soldered.

Nozzles are made of two stopcocks having a 1/8-in. hole. These are
connected to a 3/8-in. supply pipe. The nozzles should be set at
an angle of 20 deg. with the face of the disk. The nozzle or
stopcock will give better results if the discharge end is filed
parallel to the face of the disk when at an angle of 20 deg. There
should be a space of 1/16 in. between the nozzle and the blades to
allow for sufficient play, Fig. 3.

The bearings are made of 1/4-in. brass and bolted to the casing,
as shown, with 1/8-in. machine screws and nuts. Two nuts should be
placed on each screw. The pulley is made by sliding a piece of
steel pipe on the engine shaft and fastening it with machine
screws and nuts as shown in Fig. 6. If the shaft is square, lead
should be run into the segments.

The driven shaft should have a long bearing. The pulley on this
shaft is made of pieces of wood nailed together, and its
circumference cut out with a scroll saw. Flanges are screwed to
the pulley and fastened to the shaft as shown in Fig. 7.

The bearings are made of oak blocks lined with heavy tin or sheet
iron for the running surface. Motion is transmitted from the
engine to the large pulley by a thin but very good leather belt.



** Homemade Telegraph Key [21]

A simple and easily constructed telegraph key may be made in the
following manner: Procure a piece of sheet brass, about 1/32 in.
thick, and cut out a strip 3-1/2 in. long by 3/4 in. wide. Bend as
shown in Fig. 1 and drill a hole for the knob in one end and a
hole for a screw in the other. Procure a small wood knob and
fasten it in place with a small screw. Cut a strip of the same
brass 2-3/4 in. long and 5/16 in. wide and bend as shown in Fig.
2. Drill two holes in the feet for screws to fasten it to the
base, and one hole in the top part for a machine screw, and solder
a small nut on the under side of the metal over the hole.

Mount both pieces on a base 4-1/4 by 2-3/4 by 1/4 in., as in Fig.
3, and where

[Illustration: Brass Key on a Wood Base]

the screw of the knob strikes the base when pressed down, put in a
screw or brass-headed tack for a contact. Fasten the parts down
with small brass wood-screws and solder the connections beneath
the base. Binding posts from an old battery cell are used on the
end of the base. The screw on top of the arch is used to adjust
the key for a long or short stroke.
--Contributed by S. V. Cooke, Hamilton, Canada.



** Keeping Food Cool in Camps [21]

Camps and suburban homes located where ice is hard to get can be
provided with a cooling arrangement herein described that will
make a good substitute for the icebox. A barrel is sunk in the
ground in a shady place, allowing plenty of space about the
outside to fill in with gravel. A quantity of small stones and
sand is first put in wet. A box is placed in the hole over the top
of the barrel and filled in with clay or earth well tamped. The
porous condition of the gravel drains the surplus water after a
rain.

The end of the barrel is fitted with a light cover and a heavy
door hinged to the box. A small portion of damp sand is sprinkled
on the bottom of the barrel. The covers should be left open
occasionally to prevent mold and to remove any bad air that may
have collected from the contents.
--Contributed by F. Smith, La Salle, Ill.



** Homemade Work Basket [22]

Secure a cheese box about 12 in. high and 15 in. or more in
diameter. It will pay you to be careful in selecting this box. Be
sure to have the cover. Score the wood deeply with a carpenter's
gauge inside and out 3-1/2 in. from the top of the box. With
repeated scoring the wood will be almost cut through or in shape
to finish the cut with a knife. Now you will have the box in two
pieces. The lower part, 8-1/2 in. deep over all, we will call the
basket, and the smaller part will be known as the tray.

Remove the band from the cover and cut the boards to fit in the
tray flush with the lower edge, to make the bottom. Fasten with
3/4-in brads. The kind of wood used in making these boxes cracks
easily and leaves a rough surface which should be well
sandpapered.

The four legs are each 3/4-in. square and 30-1/2 in. long. The
tops should be beveled to keep them from splintering at the edges.
With a string or tape measure, find the circumference of the tray
or basket and divide this into four equal parts, arranging the lap
seam on both to come midway between two of the marks. When
assembling, make these seams come between the two back legs.

The tray is placed 1-1/4 in. from the top end and the basket 6-3/4
in. from the bottom end of the legs. Notch the legs at the lower
point about 1/8 in. deep and 1-1/4 in. wide to receive the band at
the lower end of the basket. Fasten with 3/4-in. screws, using
four to each leg, three of which are in the basket. Insert the
screws from the inside of the box into the legs.

Stain the wood before putting in the

[Illustration: Work Basket]

lining. If all the parts are well sandpapered, the wood will take
the stain nicely: Three yards of cretonne will make a very
attractive lining. Cut two sheets of cardboard to fit in the
bottom of the tray and basket. Cover them with the cretonne,
sewing on the back side. Cut four strips for the sides from the
width of the goods 5-1/2 in. wide and four strips 10 in. wide. Sew
them end to end and turn down one edge to a depth of 1 in. and
gather it at that point, also the lower edge when necessary. Sew
on to the covered cardboards. Fasten them to the sides of the tray
and basket with the smallest upholsterers' tacks. The product of
your labor will be a very neat and useful piece of furniture.
--Contributed by Stanley H. Packard, Boston, Mass.



** A Window Display [22]

A novel and attractive aeroplane window display can be easily made
in the following manner: Each aeroplane is cut from folded paper,
as shown in the sketch, and the wings bent out on the dotted
lines. The folded part in the center is pasted together. Each
aeroplane is fastened with a small thread from the point A as
shown. A figure of an airman can be pasted to each aeroplane. One
or more of the aeroplanes can be fastened in the blast of an
electric fan and kept in flight the same as a kite. The fan can be
concealed to make the display more real. When making the display,
have the background of such

[Illustration: Paper Aeroplanes in Draft]

a color as to conceal the small threads holding the aeroplanes.
--Contributed by Frederick Hennighausen, Baltimore, Md.



** How to Make a Flint Arrowhead [23]

If you live where flints abound, possess the requisite patience
and the knack of making things, you can, with the crudest of tools
and a little practice, chip out as good arrowheads as any painted
savage that ever drew a bow.

Select a piece of straight-grained flint as near the desired shape
as possible. It may be both longer and wider than the finished
arrow but it should not be any thicker. The side, edge and end
views of a suitable fragment are shown in Fig. 1. Hold the piece
with one edge or end resting on a block of wood and strike the
upper edge lightly with a hammer, a small boulder or anything that
comes handy until the piece assumes the shape shown in Fig. 2.

[Illustration: Fig.2  Fig.3  The Stone Chipped into Shape]

The characteristic notches shown in the completed arrow, Fig. 3,
are chipped out by striking the piece lightly at the required
points with the edge of an old hatchet or a heavy flint held at
right angles to the edge of the arrow. These heads can be made so
that they cannot be distinguished from the real Indian arrowheads.
--Contributed by B. Orlando Taylor, Cross Timbers, Mo.



** An Opening Handle for a Stamp Pad [23]

A stamp pad is a desk necessity and the cleanliness of one depends
on keeping it closed when it is not in use. The opening and
closing of a pad requires both hands and consequently the closing
of a pad is often neglected in order to avoid soiling the fingers.
This trouble can be avoided if the pad is fitted with a small
handle as shown in the sketch. Take the ordinary pad and work the
hinge until it opens freely.

[Illustration: Handle on Cover]

If necessary apply a little oil and spread the flanges of the
cover slightly.

Saw off the top of a common wood clothespin just above the slot,
saving all the solid part. Fasten this to the cover near the back
side in an upright position with a screw. A tap on the front side
of the pin will turn it over backward until the head rests on the
desk thus bringing the cover up in the upright position. When
through using the pad, a slight tap on the back side of the cover
will turn it down in place.
--Contributed by H. L. Crockett, Gloversville, N. Y.



** Concrete Kennel [23]

The kennel shown in the illustration is large enough for the usual
size of dog. It is cleanly, healthful and more ornamental than the
average kennel.

[Illustration: Finished Kennel]

This mission style would be in keeping with the now popular
mission and semi-mission style home, and, with slight
modifications, it could be made to conform with the ever beautiful
colonial home. It is not difficult to

[Illustration: Concrete Forms]

build and will keep in good shape for many years. The dimensions
and the manner of making the forms for the concrete, and the
location for the bolts to hold the plate and rafters, are shown in
the diagram.
--Contributed by Edith E. Lane, El Paso, Texas.



** Nutshell Photograph Novelty [24]

Split an English walnut in the center, remove the contents, and
scrape out the rough parts. Make an oval

[Illustration: Photograph in the Shell]

opening by filing or grinding. If a file is used, it should be new
and sharp. After this is done, take a small half round file and
smooth the edges into shape and good form.

The photograph print should be quite small--less than 1/2 in.
across the face. Trim the print to a size a little larger than the
opening in the shell, and secure it in place with glue or paste.
It may be well to fill the shell with cotton. Mount the shell on a
small card with glue, or if desired, a mount of different shape
can be made of burnt woodwork.
--Contributed by C. S. Bourne, Lowell, Mass.



** Spoon Holder on a Kettle [24]

In making marmalade and jellies the ingredients must be stirred
from time to time as the cooking proceeds. After stirring, some of
the mixture always remains on the spoon. Cooks often lay the spoon
on a plate or stand it against the cooking utensil with the handle
down. Both of these methods are wasteful. The accompanying
illustration shows a device made of sheet copper to hold the spoon
so that the drippings will return to the cooking utensil. The
copper is not hard to bend and it can be shaped so that the device
can be used on any pot or kettle.
--Contributed by Edwin Marshall, Oak Park, Ill.

[Illustration: Spoon Holder]



** Repairing Cracked Gramophone Records [24]

Some time ago I received two gramophone records that were cracked
in shipment but the parts were held together with the paper label.
As these were single-faced disk records, I used the following
method to stick them together: I covered the back of one with
shellac and laid the two back to back centering the holes with the
crack in one running at right angles to the crack in the other.
These were placed on a flat surface and a weight set on them.
After several hours' drying, I cleaned the surplus shellac out of
the holes and played them.

As the needle passed over the cracks the noise was hardly audible.
These records have been played for a year and they sound almost as
good as new.
--Contributed by Marion P. Wheeler, Greenleaf, Oregon.



** New Use for a Vacuum Cleaner [25]

An amateur mechanic who had been much annoyed by the insects which
were attracted to his electric lights found a solution in the
pneumatic moth trap described in a recent issue of Popular
Mechanics. He fixed a funnel to the end of the intake tube of a
vacuum cleaner and hung it under a globe. The insects came to the
light, circled over the funnel and disappeared. He captured
several pounds in a few hours.
--Contributed by Geo. F. Turl, Canton, Ill.



** Filtering with a Small Funnel [25]

In filtering a large amount of solution one usually desires some
means other than a large funnel and something to make the watching
of the process unnecessary. If a considerable quantity of a
solution be placed in a large bottle or flask, and a cork with a
small hole in it inserted in the mouth, and the apparatus
suspended in an inverted position over a small funnel so that the
opening of the cork is just below the water level in the funnel,
the filtering process goes on continuously with no overflow of the
funnel.

As soon as the solution in the funnel is below the cork, air is
let into the flask and a small quantity of new solution is let
down into the funnel. The process works well and needs no
watching, and instead of the filtrate being in a large filter
paper, it is on one small piece and can be handled with ease.
--Contributed by Loren Ward, Des Moines, Iowa.



** A Postcard Rack [25]

The illustration shows a rack for postcards. Those having houses

[Illustration: Finished Rack]

with mission-style furniture can make such a rack of the same
material as the desk, table or room furnishings and finish it in
the same manner.

The dimensions are given in the detail sketch. The two ends are
cut from 1/4-in. material, the bottom being 3/8 in. thick. Only
three pieces are required, and as they are simple in design,
anyone can cut them out with a

[Illustration: Details of the Rack]

saw, plane and pocket knife.
--Contributed by Wm. Rosenberg, Worcester, Mass.



** Substitute Shoe Horn [25]

A good substitute for a shoe horn is a handkerchief or any piece
cloth used in the following way: Allow part of the handkerchief or
cloth to enter the shoe, place the toe of the foot in the shoe so
as to hold down the cloth, and by pulling up on the cloth so as to
keep it taut around the heel the foot will slide into the shoe
just as easily as if a shoe horn were used.
--Contributed by Thomas E. Dobbins, Glenbrook, Conn.



** Building a Small Photographic Dark Room [26]

In building a photographic dark room, it is necessary to make it
perfectly light-tight, the best material to use being matched
boards. These boards are tongued and grooved and when put together
effectually prevent the entrance of light.

The next important thing to be considered is to make it
weather-tight, and as far as the sides are concerned the matched
boards will do this also, but it is necessary to cover the roof
with felt or water-proof paper.

The best thickness for the boards is 1 in., but for cheapness 3/4
in. will do as well, yet the saving is so little that the 1-in.
boards are preferable.

The dark room shown in the accompanying sketch measures 3 ft. 6
in. by 2 ft. 6 in., the height to the eaves being 6 ft. Form the
two sides shown in Fig 1, fixing the crosspieces which hold the
boards together in such positions that the bottom one will act as
a bearer for the floor, and the second one for the developing
bench. Both sides can be put together in this way, and both
exactly alike. Keep the ends of the crosspieces back from the
edges of the boards far enough to allow the end boards to fit in
against them.

One of the narrow sides can be formed in the same way, fixing the
crosspieces on to correspond, and then these three pieces can be
fastened together by screwing the two wide sides on the narrow
one.

Lay the floor next, screwing or nailing the boards to the
crosspieces, and making the last board come even with the ends of
the crosspieces, not even with the boards themselves. The single
boards can then be fixed, one on each side of what will be the
doorway, by screwing to the floor, and to the outside board of the
sides. At the top of the doorway, fix a narrow piece between the
side boards, thus leaving a rectangular opening for the door.

The roof boards may next be put on, nailing them to each other at
the ridge, and to the sides of the room at the outsides and eaves.
They should overhang at the sides and eaves about 2 in., as shown
in Figs. 3 and 4.

One of the sides with the crosspieces in place will be as shown in
Fig. 2 in section, all the crosspieces and bearers intersecting
around the room.

The door is made of the same kind of boards held together with
crosspieces, one of which is fastened so as to fit closely to the
floor when the door is hinged, and act as a trap for the light.
The top crosspiece is also fastened within 1 in. of the top of the
door for the same reason.

Light traps are necessary at the sides and top of the door. That
at the hinged side can be as shown at A, Fig. 5, the closing side
as at B, and the top as at C in the same drawing. These are all in
section and are self-explanatory. In hinging the door, three butt
hinges should be used so as to keep the joint close.

The fittings of the room are as shown sectionally in Fig. 6, but
before fixing these it is best to line the room with heavy, brown
wrapping paper, as an additional safeguard against the entrance of
light.

The developing bench is 18 in. wide, and in the middle an opening,
9 by 11 in., is cut, below which is fixed the sink. It is shown in
detail in Fig. 7, and should be zinc lined.

The zinc should not be cut but folded as shown in Fig. 8, so that
it will fit inside the sink. The bench at each side of the sink
should be fluted (Fig. 9), so that the water will drain off into
the sink. A strip should be fixed along the back of the bench as
shown in Figs. 6 and 9, and an arrangement of slats (Fig. 10),
hinged to it, so as to drop on the sink as in Fig. 6, and shown to
a larger scale in Fig. 11.

A shelf for bottles and another for plates, etc., can be fixed
above the developing bench as at D and E (Fig. 6) and another as F
in the same drawing. This latter forms the bottom of the tray
rack, which is fixed on as shown

[Illustration: Details of the Dark Rook]

in Fig. 13. The divisions of the tray rack are best fitted loosely
in grooves formed by fixing strips to the shelves and under the
bench and sink as in Fig. 13.

Extra bearing pieces will be wanted for the shelves mentioned
above, these being shown in Fig. 14. The window is formed by
cutting an opening in the side opposite the door, and fixing in it
a square of white glass with strips of wood on the inside and
putty on the outside, as in Fig. 15. A ruby glass is framed as
shown at G, Fig. 16, and arranged to slide to and fro in the
grooved runners H, which makes it possible to have white light, as
at I, or red light as at K, Fig. 16. The white glass with runners
in position is shown at L in the same drawing, but not the red
glass and frame. Ventilation is arranged for by boring a series of
holes near the floor, as at M, Fig. 6, and near the roof as at N
in the same drawing, and trapping the light without stopping the
passage of air, as shown in the sections, Fig. 17.

The finish of the roof at the gables is shown in Fig. 18, the
strip under the boards holding the felt in position when folded
under, and the same is true of the roll at the top of the roof in
Fig. 19.

The house will be much strengthened if strips, as shown in Fig.
20, are fastened in the corners inside, after lining with brown
paper, screwing them each way into the boards. The door may have a
latch or lock with a knob, but should in addition have two buttons
on the inside, fixed so as to pull it shut tightly at top and
bottom. A waste pipe should be attached to the sink and arranged
to discharge through the floor. A cistern with pipe and tap can be
fastened in the top of the dark room, if desired, or the room may
be made with a flat roof, and a tank stand on it, though this is
hardly advisable.

It is absolutely necessary that the room be well painted, four
coats at first is not too many, and one coat twice a year will
keep it in good condition.

A brick foundation should be laid so that no part of the room
touches the ground.



** The Versatile Querl [28]

"Querl" is the German name for a kitchen utensil which may be used
as an egg-beater, potato-masher or a lemon-squeezer. For beating
up an egg in a glass, mixing flour and water, or stirring cocoa or
chocolate, it is better than anything on the market.

[Illustration: Querl Made of Wood]

This utensil is made of hardwood,  preferably maple or ash. A
circular piece about 2 in. in diameter is cut from 1/2-in. stock
and shaped like a star as shown in Fig. 1, and a 3/8-in. hole
bored in the center for a handle. The handle should be at least 12
in. in length and fastened in the star as shown in Fig. 2.

In use, the star is placed in the dish containing the material to
be beaten or mixed and the handle is rapidly rolled between the
palms of the hands.
--Contributed by W. Karl Hilbrich, Erie, Pennsylvania.



** An Emergency Soldering Tool [28]

Occasionally one finds a piece of soldering to do which is
impossible to reach with even the smallest of the ordinary
soldering irons or coppers. If a length of copper wire as large as
the job will permit and sufficiently long to admit being bent at
one end to form a rough handle, and filed or dressed to a point on
the other, is heated and tinned exactly as a regular copper should
be, the work will cause no trouble on account of inaccessibility.
--Contributed by E. G. Smith, Eureka Springs, Ark.



** Smoothing Paper after Erasing [29]

When an ink line is erased the roughened surface of the paper
should be smoothed or polished so as to prevent the succeeding
lines of ink from spreading. A convenient desk accessory for this
purpose can be made of a short

[Illustration: Collar Button Ends In Wood Stick]

piece of hardwood and two bone collar buttons.

File off the head of one button at A and the base from another at
B. Bore a small hole D and E in each end of the wood handle C and
fasten the button parts in the holes with glue or sealing wax. The
handle can be left the shape shown or tapered as desired. The
small end is used for smoothing small erasures and the other end
for larger surfaces.



** A Cherry Seeder [29]

An ordinary hairpin is driven part way into a small round piece of
wood, about 3/8 in. in diameter and 2 or 2-1/2 in. long, for a
handle, as shown in the sketch. The hairpin should be a very

[Illustration: Hairpin In Stick]

small size. To operate, simply insert the wire loop into the
cherry where the stem has been pulled off and lift out the seed.
--Contributed by L. L. Schweiger, Kansas City, Mo.



** A Dovetail Joint  [29]

The illustration shows an unusual dovetail joint, which, when put
together properly is a puzzle. The tenon or tongue of the joint is
sloping on three surfaces and the mortise is cut sloping to match.
The bottom surface of the mortise is the same width at

[Illustration: Shape of Tenon and Mortise]

both ends, the top being tapering toward the base of the tongue.
--Contributed by Wm. D. Mitchell, Yonkers, New York.



** Base for Round-End Bottles [29]

The many forms of round-bottomed glass bottles used in chemical
laboratories require some special kind of support on which they
can be safely placed from time to time when the chemist

[Illustration: Base Made-of Corks]

does not, for the moment, need them. These supports should not be
made of any hard material nor should they be good conductors of
heat, as such qualities would result in frequent breakage.

A French magazine suggests making the supports from the large
corks of glass jars in which crystal chemicals are usually
supplied from the dealers. The manner of making them is clearly
shown in the sketch. Each cork is cut as in Fig. 1 and placed on a
wire ring (Fig. 2) whose ends are twisted together and the last
section of cork is cut through from the inner side to the center
and thus fitted over the wire covering the twisted ends, which
binds them together. The corks in use are shown in Fig. 3.



** Rustic Window Boxes [30]

Instead of using an ordinary green-painted window box, why not
make an artistic one in which the color does not clash with the
plants contained in it but rather harmonizes with them.

Such a window box can be made by anyone having usual mechanical
ability, and will furnish more opportunities for artistic and
original design than many other articles of more complicated
construction.

The box proper should be made a little shorter than the length of
the window to allow for the extra space taken up in trimming and
should be nearly equal in width to the sill, as shown in Fig. 1.
If the sill is inclined, as is usually the case, the box will
require a greater height in front, to make it set level, as shown
in Fig. 2.

The box should be well nailed or screwed together and should then
be painted all over to make it more durable. A number of 1/2-in.
holes should be drilled in the bottom, to allow the excess water
to run out and thus prevent rotting of the plants and box.

Having completed the bare box, it may be trimmed to suit the fancy
of the maker. The design shown in Fig. 1 is very simple and easy
to construct, but may be replaced with a panel or other design.
One form of panel design is shown in Fig. 3.

Trimming having too rough a surface will be found unsuitable for
this work as it is difficult to fasten and cannot be split as well
as smooth trimming. It should be cut the proper length before
being split and should be fastened with brads. The half-round
hoops of barrels will be found very useful in trimming, especially
for filling-in purposes, and by using them the operation of
splitting is avoided. After the box is trimmed, the rustic work
should be varnished, in order to thoroughly preserve it, as well
as improve its appearance.

[Illustration: Artistic Flower Boxes]



** Antidote for Squirrel Pest [30]

To the owner of a garden in a town where squirrels are protected
by law, life in the summer time is a vexation. First the squirrels
dig up the sweet corn and two or three replantings are necessary.
When the corn is within two or three days of being suitable for
cooking, the squirrels come in droves from far and near. They eat
all they can and carry away the rest. When the corn is gone
cucumbers, cabbages, etc., share the same fate, being partly eaten
into. At the risk of being arrested for killing the squirrels I
have used a small target rifle morning and night, but during my
absence the devastation went on steadily. Last year they destroyed
my entire corn crop. Traps do no good; can't use poison, too
dangerous. But I have solved the difficulty; it's easy.

Shake cayenne pepper over the various vegetables which are being
ruin, and observe results.



** Homemade Electric Stove [31]
By J. F. THOLL

The construction of an electric stove is very simple, and it can
be made by any home mechanic having a vise and hand drill. The
body is made of sheet or galvanized iron, cut out and drilled as
shown in Fig. 1.

Each long projection represents a leg, which is bent at right
angles on the center line by placing the metal in the jaws of a
vise and hammering the metal over flat. If just the rim is gripped
in the vise, it will give a rounding form to the lower part of the
legs. The small projections are bent in to form a support for the
bottom.

The bottom consists of a square piece of metal, as shown in Fig.
2. Holes are drilled near the edges for stove bolts to fasten it
to the bottom projections. Two of the larger holes are used for
the ends of the coiled rod and the other two for the heating-wire
terminals. The latter holes should be well insulated with
porcelain or mica. The top consists of a square piece of metal
drilled as shown in Fig. 3. Four small ears are turned down to
hold the top in place.

One end of the coiled rod is shown in Fig. 4. This illustrates how
two pins are inserted in holes, drilled at right angles, to hold
the coil on the bottom plate. The coiled rod is 3/16 in.

[Illustration: Pattern for Parts of the Electric Stove]

in diameter and 27 in. long. The rod is wrapped with sheet
asbestos, cut in 1/2-in. strips.

The length of the heating wire must be determined by a test. This
wire can be purchased from electrical stores. Stovepipe wire will
answer the purpose when regular heating wire cannot be obtained.
The wire is coiled around the asbestos-covered rod, so that no
coil will be in contact with another coil. If, by trial, the coil
does not heat sufficiently, cut some of it off and try again.
About 9-1/2 ft. of No. 26 gauge heating wire will be about right.
The connection to an electric-lamp socket is made with ordinary
flexible cord, to which is attached a screw plug for making
connections.



** Glass-Cleaning Solution [31]

Glass tumblers, tubing and fancy bottles are hard to clean by
washing them in the ordinary way, as the parts are hard to reach
with the fingers or a brush. The following solution makes an
excellent cleaner that will remove dirt and grease from crevices
and sharp corners. To 9 parts of water add 1 part of strong
sulphuric acid. The acid should be added to the water slowly and
not the water to the acid. Add as much bichromate of potash as the
solution will dissolve. More bichromate of potash should be added
as the precipitate is used in cleaning.

The chemicals can be purchased cheaply from a local drug store,
and made up and kept in large bottles. The solution can be used
over and over again. -- Contributed by Loren Ward Des Moines,
Iowa.



** Automatic-Closing Kennel Door [32]

When the neighborhood cats are retired for the night and there is
nothing more to chase, my fox terrier seems to realize that his
usefulness

[Illustration: Diagram of Closing Door]

for the day is over and begs to be put in his kennel that he may
not bark at the moon as some dogs are apt to do. This necessitates
my putting him out at a time when it may not be convenient.
Frequently in stormy weather this is a disagreeable duty and I
found a way to obviate it by making a trapdoor device for his
kennel as shown in the sketch whereby he may lock himself in when
he crosses the threshold.

The outer half A of the hinged trapdoor is made heavier than the
inner half B by a cleat, C, and a strip, D, to cause the door to
swing shut. The tripper stick E is set between cleats C and F to
hold the door open. When the dog steps on the inner half of the
trapdoor B, it falls to stop G, releasing tripper stick E (which
is heavier on the top end H) to cause it to fall clear of the path
of the trapdoor. The door then swings shut in the direction of the
arrow, the latch I engaging a slot in the door as it closes, and
the dog has locked himself in for the night. The latch I is made
of an old-fashioned gate latch which is mortised in the bottom
joist of the kennel. When releasing the dog in the morning the
door is set for the evening.
--Contributed by Victor Labadie, Dallas, Texas.



** Polishing Cloths for Silver [32]

Mix 2 lb. of whiting and 1/2 oz. of oleic acid with 1 gal. of
gasoline. Stir and mix thoroughly. Soak pieces of gray outing
flannel of the desired size--15 by 12 in. is a good size--in this
compound. Wring the surplus fluid out and hang them up to dry,
being careful to keep them away from the fire or an open flame.
These cloths will speedily clean silver or plated ware and will
not soil the hands.

In cleaning silver, it is best to wash it first in hot water and
white soap and then use the polishing cloths. The cloths can be
used until they are worn to shreds. Do not wash them. Knives,
forks, spoons and other small pieces of silver will keep bright
and free from tarnish if they are slipped into cases made from the
gray outing flannel and treated with the compound.

Separate bags for such pieces as the teapot, coffee pot, hot-water
pot, cake basket and other large pieces of silverware will keep
them bright and shining.
--Contributed by Katharine D. Morse, Syracuse, N. Y.



** A Book-Holder [32]

Books having a flexible back are difficult to hold in an upright
position when copying from them. A makeshift combination of
paperweights and other books is often used, but with
unsatisfactory results.

[Illustration: Fig 2. Box Corner Makes a Book Holder]

The book-holder shown in the sketch will hold such books securely,
allow the pages to be turned easily and conceal the smallest
possible portion of each page.

The holder can be cut out of a box corner and fitted with two
screw eyes, which have the part shown by the dotted lines at A
(Fig. 1) removed. The length of the back board determines the
slope for the book rest.
--Contributed by James M. Kane, Doylestown, Pa.



** Clamping a Cork [33]

It is aggravating to continually break the cork of the stock
mucilage bottle because of its sticking to the neck of the bottle
after a supply has been poured out. If a stove bolt is inserted
lengthwise through the cork with a washer on each end and the nut
screwed up tightly, as shown in the sketch, the cork may be made
to last longer than the supply of mucilage and can be placed in a
new bottle and used over and over again.

[Illustration: Cork Clamp]



** Withdrawing Paper from under an Inverted Bottle [33]

Invert a bottle on a piece of paper near the edge of a table top
and ask anyone to remove the paper without overturning the bottle.
They will at once jerk the paper with the result that the bottle
will turn over. To remove the paper just strike the table top with
your right fist while pulling the paper slowly with your left
hand. As you strike the table the bottle will jump and release the
paper.
--Contributed by Maurice Baudier, New Orleans, La.



** Emergency Tire Repair [33]

A bone collar button makes a good substitute for a plug in
repairing a puncture in a single-tube bicycle tire.



** Broom Holder Made of a Hinge [33]

The broom holder shown in the sketch is made of an ordinary hinge
with one wing screwed to the wall. The loose wing has a large hole
drilled in it to receive the handle of the broom. The manner of
holding the broom is plainly shown in the sketch.
--Contributed by Theodore L. Fisher; Waverly, Ill.

[Illustration: Broom Holder]



** Making Proofs before the Negative Dries [33]

A correspondent of Camera Craft makes proofs from his developed,
but unfixed, negatives, by squeezing a sheet of wet bromide paper
into contact with the wet film and giving an exposure several
times longer than would be required under ordinary conditions,
using the paper dry. If the developer is well rinsed out of the
film, the exposure to artificial light necessary to make a print
will have no injurious effect upon the negative, which is, of
course, later fixed and washed as usual.



** Flower-Pot Stand [33]

A very useful stand for flower pots can be made of a piece of
board supported by four clothes hooks. The top may be of any size
suitable for the flower pot. The hooks which serve as legs are
fastened to the under side of the board in the same manner as
fastening the hook to a wall.
--Contributed by Oliver S. Sprout, Harrisburg, Pa.

[Illustration: Flower-pot Stand]



** A Line Harmonograph  [34]

[Illustration: Harmonograph]

As an apparatus capable of exciting interest, probably nothing so
easily constructed surpasses the harmonograph. Your attention will
be completely absorbed in the ever changing, graceful sweep of the
long pendulum, the gyrations of which are faithfully recorded in
the resulting harmonogram.

A careless impetus given to the pendulum may result in a very
beautiful harmonogram, but you may try innumerable times to
duplicate this chance record without success. No two hamonograms
are exactly alike. The harmonograph, while its pendulum swings in
accordance with well known natural laws, is exceedingly erratic
when it comes to obeying any preconceived calculations of its
operator. In this uncertainty lies the charm. If time hangs
heavily or a person is slightly nervous or uneasy, a harmonograph
is a good prescription.

The prime essential in a well working harmonograph is a properly
constructed universal joint. Where such a joint is made with
pivots for its bearings, one pair of pivots are very liable to
have more friction than the other, which retards the movement and
causes the harmonograph to undergo a continuous change of axis. To
obviate this difficulty, the joint should be made similar to those
used on scales. The general appearance of such a joint is shown in
the first illustration, Fig. 1. Stirrups A and B are made of 7/8
by 1/4-in. metal. Holes are drilled in each end of these stirrups
and filed out as shown at C. The two holes shown in the center of
the stirrup A are drilled to fasten the apparatus to the ceiling.
Two corresponding holes are drilled in B to fasten the long
pendulum F to the joint. The cross of the joint D has the ends
shaped as shown at E. The rounded shoulder on E is to prevent the
cross from becoming displaced by a jar or accident. The ends of
the cross are inserted through the holes C of the stirrups, then
slipped back so the knife edges engage in the V-shaped holes of
the stirrups. The cross must be so made that the knife edges will
be in the same plane. This can be determined by placing two of the
knife edges on the jaws of a vise and then laying two rules across
the other two edges. The rules should just touch the jaws of the
vise and the two knife edges of the cross. This makes a universal
joint almost free from friction and, what is most important,
prevents the pendulum from twisting on its own axis.

The pendulum F should be made of ash or oak, 1-3/4 by 2 in., with
a length depending on the height of the ceiling. A length of 7 ft.
is about right for a 10-ft. ceiling.

A small table or platform, K, as shown in the lower part of Fig.
1, is fastened to the lower end of the pendulum as a support for
the cards on which harmonograms are made. A weight, G, of about 30
or 40 lb.-a box filled with small weights will do--is attached to
the pendulum just above the table. Another weight of about 10 lb.
is attached as shown at H. A pedestal, J, provides a means of
support for the stylus. The stylus arm should have pin-point
bearings, to prevent any side motion.

The length of the short pendulum H, which can be regulated, as
shown in Fig. 1, should bear a certain and exactly fixed relation
to the length of the main pendulum, for the swinging times of
pendulums are inversely proportionate to their lengths, and unless
the shorter pendulum is, for instance, exactly one-third,
one-fourth, one-fifth, etc., as long as the other, that is, makes
respectively 3, 4 or 5 swings to one swing of the long pendulum,
they will not harmonize and a perfect harmonogram is not obtained.

A good stylus to contain the ink is easily made from a glass tube
1/4 in. in diameter. Heat the tube in an alcohol or Bunsen flame
and then, by drawing the two portions apart and twisting at the
same time, the tube may be drawn to a sharp point. An opening of
any desired size is made in the point by rubbing it on a
whetstone. Owing to the fact that the style of universal joint
described has so little friction, the stylus point must be very

[Illustration: Lines Made with the Harmonograph]

fine, or the lines will overlap and blur. A small weight, such as
a shoe buttoner, placed on the arm near the stylus will cause
enough friction to make the pendulum "die" faster and thus remedy
the trouble.
--Contributed by Wm. R. Ingham, Rosemont, Arizona.



** Cutting Circular Holes in Thin Sheet Metal [35]

In arts and crafts work, occasion often arises to cut a perfectly
circular hole in sheet copper or brass. To saw and file it out
takes time and skill. Holes up to 3 in. in diameter can be cut
quickly and accurately with an ordinary expansive bit.

Fasten the sheet metal to a block of wood with handscrews or a
vise. Punch a hole, with a nail set or punch, in the center of the
circle to be cut, large enough to receive the spur of the
expansive bit. A few turns of the brace will cut out the circle
and leave a smooth edge.
--Contributed by James T. Gaffney, Chicago.



** Key Card for Writing Unreadable Post Cards [35]

A key card for use in correspondence on postals that makes the
matter unreadable unless the recipient has a duplicate key card is
made as follows: Rule two cards the size of postal, one for the
sender and one for the receiver, dividing them into quarters.
These quarters are subsequently divided into any convenient number
of rectangular parts-six in this case.

These parts are numbered from one to six in each quarter beginning
at the outside corners and following in the same order in each
quarter. Cut out one rectangle of each number with a sharp knife,
distributing them over the whole card. Then put a prominent figure
1 at the top of one side, 2 at the bottom and 3 and 4 on the other
side. The numbering and the cutouts are

[Illustration: The Key Card]

shown in Fig. 1. The two key cards are made alike.

The key card is used by placing it over a postal with the figure 1
at the top and writing in the spaces from left to right as usual,
Fig. 3, then put 2 at the top, Fig. 4, and proceed as before, then
3 as in Fig. 5, and 4 as in Fig. 6. The result will be a jumble of
words as shown in Fig. 2, which cannot be read to make any sense
except by use of a key card.
--Contributed by W.J. Morey, Chicago.



** Homemade Carpenter's Vise [36]

The sketch shows an easily made, quick-working wood vise that has
proved very satisfactory. The usual screw is replaced by an open
bar held on one end by a wedge-shaped block,

[Illustration: Vise Made Entirely of Wood]

and the excess taken up on the other end by an eccentric lever.
The wedge is worked by a string passing through the top of the
bench and should be weighted on the other end to facilitate the
automatic downward movement.

The capacity of the vise, of course, depends on the size and shape
of the wedge-shaped block.
--Contributed by J.H. Cruger, Cape May City, N.J.



** Toning Blue on Bromide and Platinum [36]

After some experimenting to secure a blue tone on bromide prints,
a correspondent of the Photographic Times produced a very pleasing
bluish green tint by immersing the prints in a solution composed
of 30 gr. of ferricyanide of potash, 30 gr. citrate of iron and
ammonia, 1/2 oz. acetic acid and 4 oz. of water. After securing
the tint desired, remove the prints, rinse them in clean water for
a few minutes, and then place them in a dilute solution of
hydrochloric acid. Wash the prints thoroughly and hang them up
with clips to dry.



** Cutting Loaf Bread [36]

When cutting a loaf of bread do not slice it from the outer
crusted end. Cut through the center, then cut slices from the
center toward the ends. The two cut surfaces can be placed
together, thus excluding the air and keeping the bread fresh as
long as there is any left to slice.
--Contributed by L. Alberta Norrell, Augusta, Ga.



** How to Make an Electric Toaster [37]

The electric toaster shown in the sketch is not hard to make. The
framework comprising the base and the two uprights may be made
either of hardwood or asbestos board, says Popular Electricity. If
constructed of the former, the portion of the base under the coil,
and the inside surfaces of the two uprights should be covered with
a 1/8-in. sheet of well made asbestos paper, or thin asbestos
board may be substituted for this lining. Asbestos board is to be
preferred, and this material in almost any degree of hardness may
be purchased. It can be worked into shape and will hold wood
screws. The detail drawing gives all dimensions necessary to shape
the wood or asbestos board.

After preparing the base and uprights, drill 15 holes, 1/4 in.
deep, into the inside face of each upright to support the No. 6
gauge wires shown. The wires at the top and bottom for holding the
resistance wire are covered with asbestos paper and the holes for
these wires are 3/4 in. from the top and bottom, respectively, of
the uprights. The wires that form the cage about the heater coil
and are used for a support for the toast are 15 pieces of No. 6
gauge iron wire each 8 in. long. The screws that hold the uprights
in position should have the heads countersunk on the under side of
the base. The binding-posts should now be set in position and
their protecting covering

[Illustration: Detail of Toaster]

containing the reinforced cord left until the other parts are
finished.

To assemble, secure one upright in position using 1-1/2 in.
wood-screws. Place the other upright where it belongs without
fastening it and put the stretcher wires for holding the
resistance wire in place. Put the asbestos paper on these and with
the assistance of a helper begin winding on the heater coil.

[Illustration: Toaster Complete]

Use 80 ft. of 18-per-cent No. 22 gauge German-silver wire. Wind
the successive turns of wire so they will not touch each other and
fasten at each end with a turn or two of No. 16 gauge copper wire.
When this is complete have the helper hold the stretcher wires
while you tip the unfastened upright out and insert the wires of
the cage, then fasten the upright in place.

The wire from the binding-posts to the coil may be what is known
underwriters' wire or asbestos-covered wire No. 14 gauge, which is
held in place by double-headed tacks containing an insulation at
the head. These may be procured from electrical supply houses.
Connect the reinforced cord and terminals to the binding screws
and fasten the cover in place. This toaster will take four amperes
on 110-volt circuit.



** Cabinet for the Amateur's Workshop [37]

One of the most convenient adjuncts to an amateur's workbench is a
cabinet of some sort in which to keep nails, rivets, screws, etc.,
instead of leaving them scattered all about the bench. A very
easily made cabinet for this purpose is shown in the accompanying
illustration. The case may be made of 1/2-in. white pine or white
wood of a suitable size to hold the required number of drawers
which slide on strips of the same material, cut and dressed 1/2
in. square. The drawers are made of empty cigar boxes of uniform
size,

[Illustration: Empty Cigar Boxes Used for Drawers]

which, if one is not a smoker, may be readily obtained from any
cigar dealer, as they are usually thrown away when empty.

Small knobs may be added if desired, but these are not necessary,
as the spaces shown between the drawers give ample room to grasp
them with the fingers. Labels of some kind are needed, and one of
the neatest things for this purpose is the embossed aluminum
label, such as is stamped by the well known penny-in-the-slot
machines to be found in many railroad stations and amusement
places.
--Contributed by Frederick E. Ward, Ampere, N. Y.



** Uncurling Photographs [38]

Photograph prints can be kept from curling when dry, by giving
them the same treatment as was once used on films. Immerse for 5
minutes in a bath made by adding 14 oz. of glycerine to 16 oz. of
water,



** Soldering for the Amateur [38]

Successful soldering will present no serious difficulties to
anyone who will follow a few simple directions. Certain metals are
easier to join with solder than others and some cannot be soldered
at all. Copper, brass, zinc, tin, lead, galvanized iron, gold and
silver or any combination of these metals can be easily soldered,
while iron and aluminum are common metals that cannot be soldered.

It is necessary to possess a soldering copper, a piece of solder,
tinner's acid, sandpaper or steel wool, a small file and a piece
of sal ammoniac. If the soldering copper is an old one, or has
become corroded, it must be ground or filed to a point. Heat it
until hot (not red hot), melt a little solder on the sal ammoniac,
and rub the point of the copper on it, turning the copper over to
thoroughly tin the point on each face. This process is known as
tinning the iron and is very necessary to successful work.

After the copper is tinned you may place it in the fire again,
being careful about the heat, as too hot an iron will burn off the
tinning.

The parts to be soldered must be thoroughly cleaned by
sandpapering or the use of steel wool until the metal shows up
bright. Then apply the acid only to the parts to be soldered with
a small stiff brush or a small piece of cloth fastened to a stick,
or in a bent piece of tin to form a swab.

Tinner's acid is made by putting as much zinc in commercial
muriatic acid as will dissolve. This process is best accomplished
in an open earthenware dish. After the acid has ceased to boil and
becomes cool it may be poured into a wide-mouthed bottle which has
a good top or stopper, and labeled "Poison."

Place the parts to be soldered in their correct position and apply
the hot copper to the solder, then to the joint to be soldered,
following around with the copper and applying solder as is
necessary. In joining large pieces it is best to "stick" them
together in several places to hold the work before trying to get
all around them. A little practice will soon teach the requisite
amount of solder and the smoothness required for a good job.

In soldering galvanized iron, the pure muriatic acid should be
used, particularly so when the iron has once been used. --C. G.
S., Eureka Springs, Ark.



** Washboard Holder [39]

When using a washboard it will continually slip down in the tub.
This is considerable annoyance, especially if a large tub is used.
The washboard can be kept in place with small metal hooks, as
shown in the sketch. Two of these are fastened to the back of

[Illustration: Clip on the Washboard]

the washboard in the right place to keep it at the proper slant.
--Contributed by W. A. Jaquythe, Richmond, California.



** A Mission Bracket Shelf  [39]

The shelf consists of six pieces of wood A, B, C, D, E and F. The
material can be of any wood. I have one made of mahogany finished
in natural color, and one made of poplar finished black. The
dimensions given in the detail drawings are sufficient for anyone
to make this bracket. The amount of material required is very
small and can be made from scrap, or purchased from a mill
surfaced and sanded. The parts are put together with dowel pins.
--Contributed by A. Larson, Kenosha, Wis.

[Illustration: Details of the Wall Bracket]



** How to Make a Finger Ring [39]

While the wearing of copper rings for rheumatism may be a foolish
notion, yet there is a certain galvanic action

[Illustration: Tools for Forming the Ring]

set up by the contact of the acid in the system of the afflicted
person with the metal of the ring. Apart from this, however, a
ring may be made from any metal, such as copper, brass and silver,
if such metals are in plate or sheet form, by the following
method:

All the tools necessary are a die and punch which are simple to
make and will form a ring that will fit the average finger. Take a
3/4-in. nut, B, Fig. 1, and drill out the threads. This will leave
a clear hole, 7/8 in. in diameter, or a hole drilled the desired
size in a piece of iron plate will do as well. Countersink the top
of the hole so that the full diameter of the countersink will be
1-1/4 in. This completes the die. The punch A, is made of a piece
of 5/8 in. round iron, slightly rounded on the end so that it will
not cut through the metal disk. The dimensions shown in Fig. 1 can
be changed to suit the size of the finger to be fitted.

The metal used should be about 1/16 in. thick and 1-1/4 in. in
diameter. Anneal it properly by heating and plunging in water. Lay
it on the die so that it will fit nicely in the countersink and
drive it through the hole by striking the punch with a hammer.
Hold the punch as nearly central as possible when starting to
drive the metal through the hole. The disk will come out pan
shaped, C, and it is only necessary to remove the bottom of the
pan to have a band which will leave a hole 5/8 in. in diameter and
1-1/4 in. wide. Place the band, D, Fig. 2, on a stick so that the
edges can be filed and rounded to shape. Finish with fine emery
cloth and polish. Brass rings can be plated when finished.
--Contributed by H. W. Hankin, Troy, N. Y.



** How to Bind Magazines [40]

A great many readers of Popular Mechanics Magazine save their
copies and have them bound in book form and some keep them without
binding. The bound volumes make an attractive library and will
always be valuable works of reference along mechanical lines. I
bind my magazines at home evenings, with good results. Six issues
make a well proportioned book, which gives two bound volumes each
year.

The covers of the magazines are removed, the wire binders pulled
out with a pair of pliers and the advertising pages removed from
both sides, after which it will be found that the remainder is in
sections, each section containing four double leaves or sixteen
pages. These sections are each removed in turn from the others,
using a pocket knife to separate them if they stick, and each
section is placed as they were in the magazine upon each preceding
one until all six numbers have been prepared. If started with the
January or the July issue, the pages will be numbered
consecutively through the entire pages of the six issues.

The sections are then prepared for sewing. They are evened up on
the edges by jarring on a flat surface. They are then placed
between two pieces of board and all clamped in a vise. Five cuts,
1/8 in. deep, are made with a saw across the back of the sections,
as shown in Fig. 1. Heavy plain paper is used for the flyleaves.
The paper is cut double the same as the leaves comprising the
sections, making either one or two double sections for each side
as desired.

A frame for sewing will have to be made as shown in Fig. 2 before
the work can be continued on the book. The frame is easily made of
four pieces of wood. The bottom piece A should be a little larger
than the book. The two upright pieces B are nailed to the outside
edge, and a third piece, C, is nailed across the top. Small nails
are driven part way into the base C to correspond to the saw cuts
in the sections. A piece of soft fiber string is stretched from
each nail to the crosspiece C and tied.

Coarse white thread, size 16 or larger, is used for the sewing
material. Start with the front of the book. Be sure that all
sections are in their right places and that the flyleaves are
provided in the front and back. Take the sections of the flyleaves
on top, which should be notched the same as the saw cuts in the
book sections, and place them against the strings in the frame.
Place the left hand on the inside of the leaves where they are
folded and start a blunt needle, threaded double, through the
notch on the left side of the string No. 1 in Fig. 2. Take hold of
the needle with the right hand and pass it to the left around the
string No. 1, then back through the notch on the right side.
Fasten the thread by tying or making a knot in the end and passing
the needle through it. After drawing the thread tightly, pass the
needle through the notch on the left side of the string No. 2,
passing it around the string and tying in the same manner as for
No. 1. Each section is fastened to the five strings in the same
manner, the thread being carried across from each tie from No. 1
to 2 then to 3 and so on

[Illustration: Frame for Sewing Sections]

until all strings are tied. The string No. 5 is treated in the
same manner only that the needle is run through on the left side
of the string a second time, leaving the needle on the outside in
position for the next section, which is fastened the same as the
first, the needle being passed through the notch on the right side
of the string No. 5, and then to string No.4, passing around on
the right side and back on the left and so on. Keep the thread
drawn up tightly all the time.

After the sewing is completed cut the strings, allowing about 2
in. of the ends extending on each side. The fibers of these ends
are separated and combed out so that they can be glued to the
covers to serve as a hinge. A piece of cheesecloth is cut to the
size of the back and glued to it. Ordinary liquid glue is the best
adhesive to use.

Procure heavy cardboard for the covers and cut two pieces 1/2 in.
longer and just the same width as the magazine pages. The covering
can be of cloth, leather or paper according to the taste and
resources of the maker. The covering should be cut out 1 in.
larger on all edges than both covers and space on the back. Place
the cardboard covers on the book, allowing a margin of 1/4 in. on
all edges except the back, and measure the distance between the
back edges of the covers across the back of the book.

Place the cardboard covers on the back of the covering the proper
distance apart as measured for the back, and mark around each one.
Spread thin coat of glue on the surface of each and lay them on by
the marks made. Cut a notch out of the covering so it will fold
in, and, after gluing

[Illustration: The Bound Book]

a strip of paper to the covering between the covers to strengthen
the back, fold over the outside edges of the covering and glue it
down all around.

Place the cover on the book in the right position, glue the hinges
fast to the inside of the covers, then glue the first flyleaf to
the inside of the cover on both front and back and place the whole
under a weight until dry.
--Contributed by Clyde E. Divine, College View, Nebr.



** Metal Coverings for Leather Hinges [41]

A method of making a leather hinge work as well as an ordinary
steel butt is to cover the wings with sheet metal. The metal can
be fastened with nails or screws over the parts of the leather
attached to the wood. Tinplate, iron

[Illustration: Metal Parts Screwed on Leather Hinge]

hoops, zinc or thin brass cut in neat designs will make a leather
hinge appear as well as a metal hinge.
--Contributed by Tom Hutchinson, Encanto, Cal.



** Removing Plaster from Skin [41]

A hot-water bottle held against a porous plaster will assist in
quickly removing it from the skin.



** How to Make a Cheap Bracket Saw [42]

For the frame use 3/8-in. round iron, bending it as shown in the
diagram and filing a knob on each end, at opposite sides to each
other, on which to hook the blade. For the blade an old
talking-machine

[Illustration: Hacksaw Frame and Blade]

spring or a clock spring will do nicely. Heat the spring enough to
take some of the temper out of it, in order to drill the holes in
the ends, as shown, and file in the teeth. Make the blade 12 in.
long, with 10 teeth to the inch. A and B show how the blade fits
on the frame. -Contributed by Willard J. Hays, Summitville, Ohio.



** How to Make a Cannon [42]

A cannon like the one in the cut may be made from a piece of 1-in.
hydraulic pipe, A, with a steel sleeve, B, and a long thread plug,
C. Be sure to get hydraulic pipe, or double extra heavy, as it is
sometimes called, as common gas pipe is entirely too light for
this purpose. Don't have the pipe too long or the cannon will not
make as much

[Illustration: Toy Cannon]

noise. Seven or eight inches is about the right length for a 1-in.
bore. Screw the plug and pipe up tightly and then drill a 1/16-in.
fuse hole at D.

If desired the cannon may be mounted on a block of wood, F, by
means of a U-bolt or large staple, E.
--Contributed by Carson Birkhead, Moorhead, Miss.



** Controller for a Small Motor [42]

An easy way of making a controlling and reversing device for small
motors is as follows:

Cut a piece of wood (A) about 6 in. by 4-1/2 in., and 1/4 in.
thick, and another piece (B) 6 in. by 1 in., and 1/4 in. thick.
Drive a nail through this near the center for a pivot (C). To the
under side of one end nail a copper brush (D) to extend out about
an inch. On the upper side, at the same end, nail another brush
(E) so that it projects at both sides and is bent down to the
level of the end brush. Then on the board put

[Illustration: Reverse for Motor]

a semi-circle of brass-headed tacks as shown at F, leaving a small
space at the middle and placing five tacks on either side, so that
the end brush will come in contact with each one. Connect these
tacks on the under side of the board with coils of German-silver
wire, using about 8 in. of wire to each coil. Fix these by
soldering or bending over the ends of the tacks. Then nail two
strips of copper (G) in such position that the side brush will
remain on the one as long as the end brush remains on the tacks on
that side.

Put sides about 1-1/2 in. high around this apparatus, raising the
board a little from the bottom to allow room for the coil. A lid
may be added if desired. Connect up as shown.
--Contributed by Chas. H. Boyd, Philadelphia.



** How to Make a Simple Water Rheostat [43]

[Illustration: Wiring Plan for Water Rheostat]

The materials necessary are: One 5-point wood-base switch, 4 jars,
some sheet copper or brass for plates, about 5 ft. of
rubber-covered wire, and some No. 18 gauge wire for the wiring.

The size of the jars depends on the voltage. If you are going to
use a current of low tension, as from batteries, the jars need not
be very large, but if you intend to use the electric light current
of 110 voltage it will be necessary to use large jars or wooden
boxes made watertight, which will hold about 6 or 7 gal. Each jar
to be filled with 20 parts water to 1 part sulphuric acid. Jars
are set in a row in some convenient place out of the way.

Next cut out eight copper or brass disks, two for each jar. Their
size also depends on the voltage. The disks that are placed in the
lower part of the jars are connected with a rubber covered wire
extending a little above the top of the jar.

To wire the apparatus, refer to the sketch and you will see that
jar No. 1 is connected to point No. 1 on switch; No. 2, on No. 2,
and so on until all is complete and we have one remaining point on
switch. Above the jars place a wire to suspend the other or top
disks in the solution. This wire is also connected to one terminal
on the motor and to remaining point on switch. The arm of the
switch is connected to one terminal of battery, or source of
current, and the other terminal connected direct to remaining
terminal of motor.

Put arm of switch on point No. 1 and lower one of the top disks in
jar No. 1 and make contact with wire above jars. The current then
will flow through the motor. The speed for each point can be
determined by lowering top disks in jars. The top disk in jar No.
2 is lower down than in No. 1 and so on for No. 3 and No. 4. The
connection between point No. 5 on switch, direct to wire across
jars, gives full current and full speed.



** How to Build a Toboggan Sled [44]
By A. BOETTE

The first object of the builder of a sled should be to have a
"winner" both in speed and appearance. The accompanying
instructions for building a sled are designed to produce these
results.

The sled completed should be 15 ft. 2 in. long by 22 in. wide,
with the cushion about 15 in. above the ground. For the baseboard
select a pine board 15 ft. long, 11 in. wide and 2 in. thick, and
plane it on all edges. Fit up the baseboard with ten oak
foot-rests 22 in. long, 3 in. wide and 3/4 in. thick. Fasten them
on the under side of the baseboard at right angles to its length
and 16 in. apart, beginning at the rear. At the front 24 or 26 in.
will be left without cross bars for fitting on the auto front. On
the upper side of the cross bars at their ends on each side screw
a piece of oak 1 in. square by 14 ft. long. On the upper side of
the baseboard at its edge on each side screw an oak strip 3 in.
wide by 3/4 in. thick and the length of the sled from the back to
the auto front. These are to keep the cushion from falling out.
See Fig. 1. For the back of the sled use the upper part of a
child's high chair, taking out the spindles and resetting them in
the rear end of the baseboard. Cover up the outside of the
spindles with a piece of galvanized iron.

The construction of the runners is shown by Figs. 2 and 3. The
stock required for them is oak, two pieces 30 in. by 5 in. by
1-1/4 in., two pieces 34 in. by 5 in. by 1-1/4 in., two pieces 14
in. by 6 in. by 2 in., and four pieces 14 in. by 2 in. by 1 in.
They should be put together with large screws about 3 in. long.
Use no nails, as they are not substantial enough. In proportioning
them the points A, B and C, Fig. 2, are important. For the front
runners these measurements are: A, 30 in.; B, 4 in.; C, 15-1/2
in., and for the rear runners: A, 34 in.; B, 7 in. ; C, 16-1/2 in.
The screw eyes indicated must be placed in a straight line and the
holes for them carefully centered. A variation of 1/16 in. one way
or another would cause a great deal of trouble. For the steel
runners use 3/8 in. cold-rolled steel flattened at the ends for
screw holes. Use no screws on the running surface, however, as
they "snatch" the ice.

The mechanism of the front steering gear is shown at Fig. 3. A
3/4-in. steel rod makes a good steering rod. Flatten the steering
rod at one end and sink it into the wood. Hold it in place by
means of an iron plate drilled to receive the rod and screwed to
block X. An iron washer, Z, is used to reduce friction; bevel
block K to give a rocker motion. Equip block X with screw eyes,
making them clear those in the front runner, and bolt through. For
the rear runner put a block with screw eyes on the baseboard and
run a bolt through.

Construct the auto front (Fig. 4) of  3/4-in. oak boards. The
illustration shows how to shape it. Bevel it toward all sides and
keep the edges sharp, as sharp edges are best suited for the brass
trimmings which are to be added. When the auto front is in place
enamel the sled either a dark maroon or a creamy white. First
sandpaper all the wood, then apply a coat of thin enamel. Let
stand for three days and apply another coat. Three coats of enamel
and one of thin varnish will make a fine-looking sled. For the
brass trimmings use No. 27 B. & S. sheet brass 1 in. wide on all
the front edges and pieces 3 in. square on the cross bars to rest
the feet against. On the door of the auto front put the monogram
of the owner or owners of the sled, cutting it out of sheet brass.

For the steering-wheel procure an old freight-car "brake" wheel,
brass plated. Fasten a horn, such as used on automobiles, to the
wheel.

Make the cushion of leather and stuff it with hair. The best way
is to get some strong, cheap material, such as burlap, sew up one
end and make in

[Illustration: Construction a "Winner" Toboggan Sled]

the form of an oblong bag. Stuff this as tightly as possible with
hair. Then get some upholstery buttons, fasten a cord through the
loop, bring the cord through to the underside of the cushion, and
fasten the button by slipping a nail through the knot. Then put a
leather covering over the burlap, sewing it to the burlap on the
under side. Make the cushion for the back in the same way. On top
of the cushion supports run a brass tube to serve the double
purpose of holding the cushion down and affording something to
hold on to.

If desired, bicycle lamps may be fastened to the front end, to
improve the appearance, and it is well to have a light of some
kind at the back to avoid the danger of rear-end collisions.

The door of the auto front should be hinged and provided with a
lock so that skates, parcels, overshoes, lunch, etc. may be stowed
within. A silk pennant with a monogram adds to the appearance.

If desired, a brake may be added to the sled. This can be a
wrought-iron lever 1-1/2 in. by 1/2 in. by 30 in. long, so pivoted
that moving the handle will cause the end to scrape the ice. This
sled can be made without lamps and horn at a cost of about $15, or
with these for $25, and the pleasure derived from it well repays
the builder. If the expense is greater than one can afford, a
number of boys may share in the ownership.



** Burning Inscriptions on Trees

Scrape off the bark just enough to come to the first light under
coating, which is somewhat moist. With a lead pencil make an
outline of the inscription to be burnt on the tree and bring, the
rays of a large magnifying glass not quite to a fine focus on the
same. The tree will be burnt along the pencil marks, and if the
glass is not held in one spot too long, the inscription will be
burnt in as evenly as if it had been written.
--Contributed by Stewart H. Leland, Lexington, Ill.



** How to Make Small Gearwheels Without a Lathe [46]

To make small models sundry small gears and racks are required,
either cut for the place or by using the parts from an old clock.
With no other tools than a hacksaw, some files, a compass,

[Illustration: Making Model Wheels]

and with the exercise of a little patience and moderate skill,
very good teeth may be cut on blank wheels.

First take the case of a small gearwheel, say 1 in. outside
diameter and 1/16 in. thick, with twenty-four teeth. Draw a circle
on paper, the same diameter as the wheel. Divide the circumference
into the number of parts desired, by drawing diameters, Fig. 1.
The distance AB will be approximately the pitch. Now describe a
smaller circle for the base of the teeth and halfway between these
circles may be taken as the pitch circle.

Now describe a circle the same size as the largest circle on a
piece of 1/16-in. sheet metal, and having cut it out and filed it
up to this circle, fasten the marked-out paper circle accurately
over it with glue. Saw-cuts can now be made down the diameters to
the smaller circle with the aid of a saw guide, Fig. 2, made from
1/16-in. mild steel or iron. This guide should have a beveled
edge, E, from F to G, to lay along the line on which the saw-cut
is to be made. The straight-edge, CD, should be set back one-half
the thickness of the saw-blades, so that the center of the blade,
when flat against it, will be over the line FG. A small clearance
space, FC, must be made to allow the teeth of the saw to pass.

The guide should then be placed along one of the diameters and
held in position until gripped in the vise, Fig. 3. The first
tooth may now be cut, care being taken to keep the blade of the
saw flat up to the guiding edge. The Model Engineer, London, says
if this is done and the saw-guide well made, the cut will be
central on the line, and if the marking-out is correct the teeth
will be quite uniform all the way round. A small ward file will be
needed to finish off the teeth to their proper shape and
thickness.

In making a worm wheel the cuts must be taken in a sloping
direction, the slope and pitch depending on the slope and pitch of
the worm thread, which, though more difficult, may also be cut
with a hacksaw and file.

A bevel wheel should be cut in the same manner as the spur wheel,
but the cut should be deeper on the side which has the larger
diameter. To cut a rack the pitch should be marked along the side,
and the guide and saw used as before (Fig. 4).



** How to Make Four Pictures on One Plate [46]

Secure two extra slides for the plate holders and cut one corner
out on one

[Illustration: Four Photos on One Plate]

of them, as shown in Fig. 1. Make a hole in the other, as shown in
Fig. 2. With a lead pencil draw on the ground glass one line
vertical and one horizontal, each in the center. This will divide
the ground glass into four equal parts.

Focus the camera in the usual manner, but get the picture desired
to fill only one of the parts on the ground glass. Place the
plate-holder in position and draw the regular slide; substitute
one of the slides prepared and expose in the usual way.

If a small picture is to be made in the lower left-hand corner of
the plate, place the prepared slide with the corner cut, as shown
in Fig. 1. The slide may be turned over for the upper left hand
corner and then changed for slide shown in Fig. 2 for the upper
and lower right-hand corners.



** Electric Blue-Light Experiment  [47]

[Illustration: Electric Blue-light]

Take a jump-spark coil and connect it up with a battery and start
the vibrator. Then take one outlet wire, R, and connect to one
side of a 2-cp. electric lamp, and the other outlet wire, B, hold
in one hand, and press all fingers of the other hand on globe at
point A. A bright, blue light will come from the wires in the lamp
to the surface of the globe where the fingers touch. No shock will
be perceptible.



** Interesting Electrical Experiment  [47]

The materials necessary for performing this experiment are:
Telephone receiver, transmitter, some wire and some carbons,
either the pencils for arc lamps, or ones taken from old dry
batteries will do.

Run a line from the inside of the house to the inside of some
other building and fasten it to one terminal of the receiver. To
the other terminal fasten another piece of wire and ground it on
the water faucet in the house. If there is no faucet in the house,
ground it with a large piece of zinc.

Fasten the other end to one terminal of the transmitter and from
the other terminal of the same run a wire into the ground. The
ground here should consist either of a large piece of carbon, or
several pieces bound tightly together.

[Illustration: A Unique Battery]

If a person speak into the transmitter, one at the receiver can
hear what is said, even though there are no batteries in the
circuit. It is a well known fact that two telephone receivers
connected up in this way will transmit words between two persons,
for the voice vibrating the diaphragm causes an inductive current
to flow and the other receiver copies these vibrations. But in
this experiment, a transmitter which induces no current is used.
Do the carbon and the zinc and the moist earth form a battery?
--Contributed by Wm. J. Slattery, Emsworth, Pa.



** A Cheap Fire Alarm [47]

An electrical device for the barn that will give an alarm in case
of fire is shown in the accompanying diagram. A is a wooden block,
which is fastened under the loft at a gable end of the barn; B is
an iron weight attached to the string C, and this string passes up
through the barn to the roof, then over a hook or pulley and
across the barn, under the gable, and is fastened to the opposite
end of the barn.

D D are binding posts for electric wires. They have screw ends, as
shown, by which means they are fastened to the wooden block A.
They also hold the brass piece E and the strip of spring brass F
in place against the wooden block. G is a leather strap fastened
to the weight B and the spring F connected to the latter by a
small sink bolt.

[Illustration: Electric Fire Alarm]

At the house an electric bell is placed wherever convenient.
Several battery cells, of course, are also needed. Dry batteries
are most convenient. The battery cells and bell are connected in
the usual manner, and one wire from the bell and one from the
battery are strung to the barn and connected to the binding posts
D D.

If a fire occurs in the hay-mow the blaze will generally shoot
toward the gable soon after it starts, and will then burn the
string C, which allows the weight B to fall and pull the brass
spring against the iron piece E, which closes the circuit and
rings the bell in the house.

If desired, the string may be stretched back and forth under the
roof several times or drawn through any place that is in danger of
fire.
--Contributed by Geo. B. Wrenn, Ashland, Ohio.



** How to Make a Small Electric Furnace [48]

Take a block of wood and shape into a core. One like a loaf of
bread, and about that size, serves admirably. Wrap a layer of
asbestos around it and cover this with a thin layer of
plaster-of-paris. When the plaster is nearly dry wind a coil of
No. 36 wire around it, taking care that the wire does not touch
itself anywhere. Put another course of plaster-of-paris on this,
and again wind the wire around it. Continue the process of
alternate layers of plaster and wire until 500 ft. or more of the
latter has been used, leaving about 10 in. at each end for
terminals. Then set the whole core away to dry.

For a base use a pine board 10 in. by 12 in. by 1 in. Bore four
holes at one end for binding-posts, as indicated by E E. Connect
the holes in pairs by ordinary house fuse wire. At one side secure
two receptacles, B B, and one single post switch, C. Place another
switch at I and another binding-post at F. The oven is now ready
to be connected.

Withdraw the wooden core from the coils of wire and secure the
latter by bands of tin to the board. Connect the ends of the wire
to binding-posts E and F, as shown. From the other set of
binding-posts, E, run a No. 12 or No. 14 wire, connecting lamp
receptacles, B B, and switch, C, in parallel. Connect these three
to switch, D, in series with binding-post, F, the terminal of the
coil. Place 16-cp. lights in the receptacles and connect the fuses
with a 110-volt lighting circuit. The apparatus is now ready for
operation. Turn on switch, D, and the lamps, while C is open. The
coil will commence to become warm, soon drying out the
plaster-of-paris. To obtain more heat

[Illustration: Electric Furnace]

open one lamp, and to obtain still more open the other and close
switch C.
--Contributed by Eugene Tuttles, Jr., Newark, Ohio.



** How to Make an Ammeter [49]

Every amateur mechanic who performs electrical experiments will
find use for an ammeter, and for the benefit of those who wish to
construct such an instrument the following description is given:
The operative principle

[Illustration: Complete Ammeter and Details]

of this instrument is the same as that of a galvanometer, except
that its working position is not confined to the magnetic
meridian. This is accomplished by making the needle revolve in a
vertical instead of a horizontal plane. The only adjustment
necessary is that of leveling, which is accomplished by turning
the thumbscrew shown at A, Fig. 1, until the hand points to zero
on the scale.

First make a support, Fig. 2, by bending a piece of sheet brass to
the shape indicated and tapping for the screws CC. These should
have hollow ends, as shown, for the purpose of receiving the
pivoted axle which supports the hand. The core, Fig. 3, is made of
iron. It is 1 in. long, 1/4 in. wide and 1/8 in. thick. At a point
a little above the center, drill a hole as shown at H, and through
this hole drive a piece of knitting-needle about 1/2 in. long, or
long enough to reach between the two screws shown in Fig. 2. The
ends of this small axle should be ground pointed and should turn
easily in the cavities, as the sensitiveness of the instrument
depends on the ease with which this axle turns.

After assembling the core as shown in Fig. 4, it should be filed a
little at one end until it assumes the position indicated. The
pointer or hand, Fig. 5, is made of wire, aluminum being
preferable for this purpose, although copper or steel will do.
Make the wire 4-1/2 in. long and make a loop, D, 1/2 in. from the
lower end. Solder to the short end a piece of brass, E, of such
weight that it will exactly balance the weight of the hand. This
is slipped on the pivot, and the whole thing is again placed in
position in the support. If the pointer is correctly balanced it
should take the position shown in Fig. 1, but if it is not exactly
right a little filing will bring it near enough so that it may be
corrected by the adjusting-screw.

Next make a brass frame as shown in Fig. 6. This may be made of
wood, although brass is better, as the eddy currents set up in a
conductor surrounding a magnet tend to stop oscillation of the
magnet. (The core is magnetized when a current flows through the
instrument.) The brass frame is wound with magnet wire, the size
depending on the number of amperes to be measured. Mine is wound
with two layers of No. 14 wire, 10 turns to each layer, and is
about right for ordinary experimental purposes. The ends of the
wire are fastened to the binding posts B and C, Fig. 1.

A wooden box, D, is then made and provided with a glass front. A
piece of paper is pasted on a piece of wood, which is then
fastened in the box in such a position that the hand or pointer
will lie close to the paper scale. The box is 5-1/2 in. high, 4
in. wide and 1-3/4 in. deep, inside measurements. After everything
is assembled put a drop of solder on the loop at D, Fig. 5, to
prevent it turning on the axle.

To calibrate the instrument connect as shown in Fig. 7, where A is
the homemade ammeter; B, a standard ammeter; C, a variable
resistance, and D, a battery, consisting of three or more cells
connected in multiple. Throw in enough resistance to make the
standard instrument read 1 ohm [sic: ampere] and then put a mark
on the paper scale of the instrument to be calibrated. Continue in
this way with 2 amperes, 3 amperes, 4 amperes, etc., until the
scale is full. To make a voltmeter out of this instrument, wind
with plenty of No. 36 magnet wire instead of No. 14, or if it is
desired to make an instrument for measuring both volts and
amperes, use both windings and connect to two pairs of binding
posts.
--Contributed by J.E. Dussault, Montreal.



** How to Make a Three-Way Cock for Small Model-Work [50]

[Illustration: Three-way Valve]

In making models of machines it is often necessary to contrive
some method for a 3- or 4-way valve or cock. To make one, secure a
pet cock and drill and tap hole through, as shown in the cut. If
for 3-way, drill in only to the opening already through, but if
for a 4-way, drill through the entire case and valve. Be sure to
have valve B turned so as to drill at right angles to the opening
through it. After drilling, remove the valve, take off the burr
with a piece of emery paper and replace ready for work.



** Easy Experiments with Electric-Light Circuit [50]

An electric-light circuit will be found much less expensive than
batteries for performing electrical experiments. The sketch shows
how a small arc light and motor may be connected to the light
socket, A. The light is removed and a plug with wire connections
is put in its place. One wire runs to the switch, B, and the other
connects with the water rheostat, which is used for reducing the
current.

[Illustration: Arc-Light Motor and Water Rheostat]

A tin can, C is filled nearly to the top with salt water, and a
metal rod, D, is passed through a piece of wood fastened at the
top of the can. When the metal rod is lowered the current
increases, and as it is withdrawn the current grows weaker. In
this way the desired amount of current can be obtained.

By connecting the motor, E, and the arc light, F, as shown, either
one may be operated by turning switch B to the corresponding
point. The arc light is easily made by fastening two electric
light carbons in a wooden frame like that shown. To start the
light, turn the current on strong and bring the points of the
carbons together; then separate slightly by twisting the upper
carbon and at the same time drawing it through the hole.



** How to Make an Interrupter [51]

The Wenult interrupter is an instrument much used on large coils
and is far more efficient than the usual

[Illustration: Details of Interrupter]

form of vibrators. It can also be used with success on small coils
as well as large. Although it is a costly instrument to purchase,
it can be made with practically no expense and the construction is
very simple.

First procure a wide-mouthed bottle about 4 in. high, provided
with a rubber stopper. This stopper should be pierced, making two
holes about 1/4 in. in diameter. From a sheet of lead 1/16 in. in
thickness

[Illustration: The Completed Instrument]

cut a piece shaped like A, Fig. 1. Common tea lead folded several
times will serve the purpose. When in the bottle this lead should
be of such a size that it will only reach half way around, as
shown in B. To insert the lead plate, roll it up so it will pass
through the neck of the bottle, then smooth it out with a small
stick until it fits against the side, leaving the small strip at
the top projecting through the neck of the bottle. Bend this strip
to one side and fit in the stopper, as shown in C. A small
binding-post is fastened at the end of the strip.

Having fixed the lead plate in position, next get a piece of glass
tube having a bore of about 1/32 of an inch in diameter. A piece
of an old thermometer tube will serve this purpose. Insert this
tube in the hole in the stopper farthest from the lead plate. Get
a piece of wire that will fit the tube and about 6 in. long, and
fasten a small binding-post on one end and stick the other into
the tube. This wire should fit the hole in the tube so it can be
easily moved. In the hole nearest the lead plate insert a small
glass funnel.

The interrupter as it is when complete is shown at D, Fig. 1.
Having finished the interrupter, connect it with the
electric-light circuit as shown in Fig. 2. Fill the bottle with
water to about the line as shown in D, Fig. 1. Adjust the wire in
the small glass tube so that it projects about 1/8 in. Add
sulphuric acid until the water level rises about 1/16 in. Turn on
the current and press the button, B. If all adjustments are
correct, there will be a loud crackling noise from the
interrupter, a violet flame will appear at the end of the wire and
a hot spark will pass between the secondary terminals. If the
interrupter does not work at first, add more sulphuric acid
through the funnel and press the wire down a little more into the
liquid. A piece of wood, A, Fig. 2, should be inserted in vibrator
to prevent it from working.
--Contributed by Harold L. Jones, Carthage, N. Y.



** A Miniature "Pepper's Ghost" Illusion [52]

Probably many readers have seen a "Pepper's Ghost" illusion at
some amusement place. As there shown, the audience is generally
seated in a dark room at the end of which there is a stage with
black hangings. One of the audience is invited onto the stage,
where he is placed in an upright open

[Illustration: Pepper's Ghost]

coffin. A white shroud is thrown over his body, and his clothes
and flesh gradually fade away till nothing but his skeleton
remains, which immediately begins to dance a horrible rattling
jig. The skeleton then fades away and the man is restored again.

A simple explanation is given in the Model Engineer. Between the
audience and the coffin is a sheet of transparent glass, inclined
at an angle so as to reflect objects located behind the scenes,
but so clear as to be invisible to the audience and the man in the
coffin. At the beginning the stage is lighted only from behind the
glass. Hence the coffin and its occupant are seen through the
glass very plainly. The lights in front of the glass (behind the
scenes) are now raised very gradually as those behind the glass
are turned down, until it is dark there. The perfectly black
surface behind the glass now acts like the silver backing for a
mirror, and the object upon which the light is now turned--in this
case the skeleton--is reflected in the glass, appearing to the
audience as if really occupying the stage.

The model, which requires no special skill except that of
carpentry, is constructed as shown in the drawings.

The box containing the stage should be 14 in. by 7 in. by 7-1/2
in., inside dimensions. The box need not be made of particularly
good wood, as the entire interior, with the exception of the
glass, figures and lights, should be colored a dull black. This
can well be done by painting with a solution of lampblack in
turpentine. If everything is not black, especially the joints and
background near A, the illusion will be spoiled.

The glass should be the clearest possible, and must be thoroughly
cleansed. Its edges should nowhere be visible, and it should be
free from scratches and imperfections. The figure A should be a
doll about 4 in. high, dressed in brilliant, light-colored
garments. The skeleton is made of papier maché, and can be bought
at Japanese stores. It should preferably be one with arms
suspended by small spiral springs, giving a limp, loose-jointed
effect. The method of causing the skeleton to dance is shown in
the front view. The figure is hung from the neck by a blackened
stiff wire attached to the hammer wire of an electric bell, from
which the gong has been removed. When the bell works he will kick
against the rear wall, and wave his arms up and down, thus giving
as realistic a dance as anyone, could expect from a skeleton.

The lights, L and M, should be miniature electric lamps, which can
be run by three dry cells. They need to give a fairly strong
light, especially L, which should have a conical tin reflector to
increase its brilliancy and prevent its being reflected in the
glass.

Since the stage should be some distance from the audience, to aid
the illusion, the angle of the glass and the inclination of the
doll, A, has been so designed that if the stage is placed on a
mantle or other high shelf, the image of A will appear upright to
an observer sitting in a chair some distance away, within the
limits of an ordinary room. If it is desired to place the box
lower down, other angles for the image and glass may be found
necessary, but the proper tilt can be found readily by experiment.

The electric connections are so simple that they are not shown in
the drawings. All that is necessary is a two-point switch, by
which either L or M can be placed in circuit with the battery, and
a press button in circuit with the bell and its cell.

If a gradual transformation is desired, a double-pointed rheostat
could be used, so that as one light dims the other increases in
brilliancy, by the insertion and removal of resistance coils.

With a clear glass and a dark room this model has proved to be
fully as bewildering as its prototype.



** Experiment with Colored Electric Lamps [53]

To many the following experiment may be much more easily performed
than explained: Place the hand or other object in the light coming
from two incandescent lamps, one red and

[Illustration: Two-Colored Hand]

one white, placed about a foot apart, and allow the shadow to fall
on a white screen such as a table-cloth. Portions of the shadow
will then appear to be a bright green. A similar experiment
consists in first turning on the red light for about a minute and
then turning it off at the same time that the white one is turned
on. The entire screen will then appear to be a vivid green for
about one second, after which it assumes its normal color.



** To Explode Powder with Electricity [53]

A 1-in. hole was bored in the center of a 2-in. square block. Two
finishing nails were driven in, as shown in the sketch. These were
connected to terminals of an induction coil. After everything was
ready the powder was poured in the hole and a board weighted with
rocks placed over the block. When the button is pressed

[Illustration: Exploding Powder]

or the circuit closed in some other way the discharge occurs. The
distance between the nail points--which must be bright and
clean--should be just enough to give a good, fat spark.
--Contributed by Geo. W. Fry, San Jose, Cal.



** Simple Wireless System [54]

The illustrations will make plain a simple and inexpensive
apparatus for

[Illustration: Simple Wireless System]

wireless telegraphy by which I have had no difficulty in sending
messages across 1-1/2 miles of water surface. It is so simple that
the cuts scarcely need explanation. In Fig. 1 is seen the sending
apparatus, consisting of a 40-cell battery connected with two
copper plates 36 by 36 by 1/8 in. The plates are separated 6 in.
by a piece of hard rubber at each end.

In Fig. 2 are seen duplicates of these insulated plates, connected
with an ordinary telephone receiver. With this receiver I can hear
distinctly the electric signals made by closing and opening the
Morse key in Fig. 1, and I believe that in a short time I shall be
able to perfect this system so as to send wireless messages over
long distances.
--Contributed by Dudley H. Cohen, New York.



** Stop Crawling Water Colors [54]

To prevent water colors from crawling, add a few drops of ammonia
or lime water, or a solution of sal soda.



** Small Electrical Hydrogen Generator [54]

A small hydrogen generator may be made from a fruit jar, A (see
sketch), with two tubes, B and C, soldered in the top. The plates
E can be made of tin or galvanized iron, and should be separated
about 1/8 in. by small pieces of wood. One of these plates is
connected to metal top, and the wire from the other passes through
the tube B, which is filled with melted rosin or wax, to make it
airtight. This wire connects to one side of a battery of two
cells, the other wire being soldered to the metal top of the jar,
as shown. The jar is partly filled with a very dilute solution of
sulphuric acid, about 1 part of acid to 20 of water.

When the current of electricity passes between the plates E,
hydrogen gas is generated, which rises and passes through the
rubber hose D, into the receiver G. This is a wide-mouth bottle,
which is filled with water and inverted over a pan of water, F.

[Illustration: Hydrogen Generator]

The gas bubbling up displaces the water and fills the bottle.

If the receiver is removed when half full of gas, the remaining
space will be filled with air, which will mix with the gas and
form an explosive mixture. If a lighted match is then held near
the mouth of the bottle a sharp report will be heard.

If the bottle is fitted with a cork containing two wires nearly
touching, and the apparatus connected with an induction coil, in
such a manner that a spark will be produced inside the bottle, the
explosion will blowout the cork or possibly break the bottle.
Caution should be used to avoid being struck by pieces of flying
glass if this experiment is tried, and under no condition should a
lighted match or spark be brought near the end of the rubber hose
D, as the presence of a little air in the generator will make an
explosive mixture which would probably break the jar.



** Gasoline Burner for Model Work [55]

When making a small model traction engine or a locomotive the
question arises, "What shall the fuel be?" If you have decided to
use gasoline, then a suitable burner is necessary. A piece of
brass tubing about 3 in. in diameter and 6 in. long with caps
screwed on both ends and fitted with a filling plug and a bicycle
valve makes a good gasoline supply tank, says the Model Engineer,
London. The bicycle valve is used to give the tank an air pressure
which forces the gasoline to the burner.

The burner is made from a piece of brass tube, A, as is shown in
the illustration, 1/2 in. in diameter and 2-1/2 in. long, which is
plugged up at both ends, one end being drilled and reamed out to
5/16 in. Three rows of holes 1/16 in. in diameter are drilled in
the brass tube. One row is drilled to come directly on top, and
the other two at about 45 degrees from the vertical. It is then
fitted to a sheet steel base, B, by means of the clips, C C, Fig.
1. A piece of 1/8-in. copper pipe, P, is then coiled around the
brass tube, A, which forms the vaporizing coil. This coil should
have a diameter

[Illustration: Gasoline Burner]

of only 1 in. One end of the copper tube is bent around so it will
point directly into the reamed-out hole in the end of the brass
tube, A. A nipple, N, is made by drilling a 1/8-in. hole halfway
through a piece of brass and tapping to screw on the end of the
1/8-in. copper pipe. A 1/64-in. hole is then drilled through the
remaining part of the nipple. The other end of the copper tube is
connected to the supply tank. The distance between the nipple, N,
and the ends of the tube, A, should be only 5/16 of an inch. Fig.
2 shows the end view.



** A Homemade Telephone Receiver [55]

A telephone receiver that will do good work may be built very
cheaply as follows: For the case use an ordinary 1/2-lb.
baking-powder box with a piece of heavy wire soldered on the
inside, 1-5/16 in. from the bottom. For the magnet use a piece of
round hardened steel about 3/8 in. in diameter and 1-1/4 in. long.
If desired, a piece of an old round file may be used for the
magnet core, which should be magnetized previous to assembling,
either by passing a current of electricity around it, or by direct
contact with another magnet. The steel core should be wound with
about 250 ft. of No. 36 insulated wire, the ends of which should
be soldered to a piece of

[Illustration: Telephone Receiver]

lamp cord, passed through a hole in the bottom of the can and
knotted inside to prevent pulling out.

A disk of thin sheet-iron, such as is used by photographers for
tintypes (Ferrotype), should be cut to the diameter of the can,
taking care not to bend the iron. The magnet should then be placed
in the bottom of the can in an upright position and enough of a
melted mixture of beeswax and resin poured in to hold it in
position.

While the wax is still in a plastic condition the magnet should be
located centrally and adjusted so that the end will be 1/16 in. or
less below the level of the top of the copper ring.

After the wax has hardened the disk is slipped in and fastened
tightly by a ring of solder when the instrument is ready for use.



** How to Bind Magazines [56]

An easy way to bind Popular Mechanics in volumes of six months
each is to arrange the magazines in order and tie them securely
both ways with a strong cord. It is well to put two or three
sheets of tough white paper, cut to the size of the pages, at the
front and back for fly leaves.

Clamp the whole in a vise or clamp with two strips of wood even
with the back edges of the magazines. With a sharp saw cut a slit
in the magazines and wood strips about 1/2 in. deep and slanting
as shown at A and B, Fig. 1. Take two strips of stout cloth, about
8 or 10 in. long and as wide as the distance between the bottoms
of the sawed slits. Lay these over the back edge of the pack and
tie securely through the slits with a string thread--wrapping and
tying several times (C, Fig. 2).

If you have access to a printer's paper knife, trim both ends and
the front edge; this makes a much nicer book, but if the paper
knife cannot be used, clamp the whole between two boards and saw
off the edges, boards and all, smoothly, with a fine saw.

Cut four pieces of cardboard, 1/4 in. longer and 1/4 in. narrower
than the magazines after they have been trimmed. Lay one piece of
the board on the book and under the cloth strips. Use ordinary
flour paste and paste the strips to the cardboard and then rub
paste all over the top of the strips and the board. Rub paste over
one side of another piece of board and put it on top of the first
board and strips, pressing down firmly so that the strips are held
securely between the two boards. Turn the book over and do the
same with the other two boards.

After the paste has dried a few minutes take a piece of strong
cloth, duck or linen, fold and cut it 1 in. larger all around than
the book, leaving the folded edge uncut. Rub paste over one of the
board backs and lay one end of the cloth on it, smoothing and
creasing as shown at A, Fig. 3. Turn the book over and paste the
other side. The back edges should have a good coat of paste and a
strip of paper

[Illustration: Process of Homemade Binding]

the width of the thickness of the pack pasted on before pasting
the cloth to the second board back.

Cut off the corners and fold over the edges of the cloth, pasting
them down (Fig. 4). Rub paste on one side of a fly leaf and press
the back down on it. Turn the book over and paste a fly leaf to
the other back after the edges of the cloth have been folded down.
The backs must not be opened until the fly leaves are thoroughly
dry. Trim and tuck in the ends of the strip at the back edge.

When fixed this way your magazines make one of the most valuable
volumes you can possibly add to your library of mechanical books.
--Contributed by Joseph N. Parker, Bedford City, Va.



** A Homemade Acetylene-Gas Generator [57]

A simple acetylene-gas generator used by myself for several years
when

[Illustration: Acetylene Gas Generator]

out on camping trips was made of a galvanized iron tank, without a
head, 18 in. in diameter and 30 in. deep, B, as shown in the
sketch. Another tank, A, is made the same depth as B, but its
diameter is a little smaller, so that inverted it will just slip
easily into the tank B. In the bottom, or rather the top now, of
tank A is cut a hole, and a little can, D, is fitted in it and
soldered. On top and over can D is soldered a large tin can screw.
A rubber washer is fitted on this so that when the screw top, E,
is turned on it, the joint will be gas tight. Another can, C,
which will just slip inside the little can, is perforated with a
number of holes. This can C is filled about half full of broken
pieces of carbide and then placed in the little can D. A gas cock,
H, is soldered onto tank A, as shown, from which the gas may be
taken through a rubber tube. Fill tank B with water and set tank A
into it. This will cause some air to be enclosed, which can be
released by leaving the cock open until tank A settles down to the
point where the water will begin to run in the perforations of the
little tank. The water then comes in contact with the carbide and
forms gas, which expands and stops the lowering of tank A. Then
the cock must be closed and tubing attached. It is dangerous to
attempt to strike a match to light a jet or the end of the cock
while air is escaping and just as the first gas is being made.
Wait until the tank is well raised up before doing this.
--Contributed by James E. Noble, Toronto, Ont.



** Homemade Annunciator [57]

When one electric bell is operated from two push-buttons it is
impossible to tell which of the two push-buttons is being operated
unless an annunciator or similar device is used. A very simple
annunciator for indicating two numbers can be made from a small
box, Fig. 1, with an electric-bell magnet, A, fastened in the
bottom. The armature, B, is pivoted in the center by means of a
small piece of wire and has an indicator or hand, C, which moves
to either right or left, depending on which half of the magnet is
magnetized. If the back armature, D, of the magnet is removed the
moving armature will work better, as this will prevent the
magnetism from acting on both ends of the armature.

The wiring diagram, Fig. 2, shows how the connections are to be
made. If the pushbutton A is closed; the bell will ring and the
pointer will point at 1,

[Illustration: Annuciator and Wiring Diagram]

while the closing of the push-button B will ring the bell and move
the pointer to 2.
--Contributed by H. S. Bott, Beverly, N. J.



** How to Make a Box Kite [58]

As some of the readers of Amateur Mechanics may desire to build a
box kite, a simple method of constructing one of the modern type
is given in detail as follows: The sticks should be made of
straight grained wood, which may be either spruce, basswood or
white pine. The longitudinal corner spines, A A, should be 3/8 in.
square by 42 in. long, and the four diagonal struts, B, should be
1/4 in. by 1/2 in., and about 26 in. long. Two cloth bands should
be made to the exact dimensions given in the sketch and fastened
to the four longitudinal sticks with 1 oz. tacks. It is well to
mark the positions of the sticks on the cloth bands, either with a
soft lead-pencil or crayon, in order to have the four sides of
each band exactly equal. The ends of the bands should be lapped
over at least 1/2 in. and sewed double to give extra strength, and
the edges should be carefully hemmed, making the width, when
finished, exactly 12 in. Probably the best cloth for this purpose
is nainsook, although lonsdale cambric or lightweight percaline
will answer nearly as well.

The diagonal struts, B, should be cut a little too long, so that
they will be slightly bowed when put in position, thus holding the
cloth out taut and flat. They should be tied together at the
points of intersection and the ends should be wound with coarse
harness maker's thread, as shown at C, to prevent splitting. The
small guards, D, are nailed or glued to the longitudinal sticks to
prevent the struts slipping out of position. Of course the ends of
the struts could be fastened to the longitudinal strips if
desired, but if made as described the kite may be readily taken
apart and rolled up for convenience in carrying.

The bridle knots, E, are shown in detail at H and J. H is a square
knot, which may be easily loosened and

[Illustration: Detail of Box Kite]

shifted to a different position on the bridle, thus adjusting the
lengths of F and G. A bowline knot should be tied at J, as shown,
to prevent slipping. If the kite is used in a light wind, loosen
the square knot and shift nearer to G, thus shortening G and
lengthening F, and if a strong wind is blowing, shift toward F,
thereby lengthening G and making F shorter. In a very strong wind
do not use the bridle, but fasten a string securely to the stick
at K.
--Contributed by Edw. E. Harbert, Chicago.



** Lubricating a Camera Shutter [58]

An experienced photographer uses blacklead [graphite] for grooves
about a camera or holder. A small quantity is rubbed well into the
grooves and on the edges of shutters, that refuse to slide easily,
with gratifying results. Care must be taken to allow no dust to
settle in the holders, however.



** Simple Open-Circuit Telegraph Line [59]

By using the circuit shown in the sketch for short-distance
telegraph lines, the extra switches and wiring found in many
circuits are done away with. Closing either key will operate both
sounders, and, as the resistance of

[Illustration: Simple Telegraph Line]

the sounders is very high, the batteries do not run down for a
long time.
--Contributed by A. D. Stoddard, Clay Center, Kan.



** How to Make a Thermo Battery [59]

A thermo battery, for producing electricity direct from heat, can
be made of a wooden frame, A, with a number of nails, B, driven in
the vertical piece and connected in series with heavy copper
wires, C. The connections should all be soldered to give good
results, as the voltage is

[Illustration: Thermo Battery]

very low and the resistance of an unsoldered joint would stop the
current. The heat may be supplied by an alcohol lamp or other
device, and the current may then be detected by means, of a simple
galvanometer consisting of a square spool of No. 14 or No. 16
single-covered wire, E, with a pocket compass, F, placed on top.
Turn the spool in a north and south direction, or parallel with
the compass needle. Then, when the nail heads are heated and the
circuit completed, the needle will swing around it at right angles
to the coils of wire. Applying ice or cold water to the nail heads
will reverse the current.
--Contributed by A. C. A., Chicago.



** How to Discharge a Toy Cannon by Electricity [59]

A device for discharging a toy cannon by electricity can be easily
made by using three or four dry batteries, a switch and a small
induction coil

[Illustration: Electrical Attachment for Discharging Toy Cannon]

capable of giving a 1/8-in. spark. Fasten a piece of wood, A, to
the cannon, by means of machine screws or, if there are no
trunnions on the cannon, the wood may be made in the shape of a
ring and slipped on over the muzzle. The fuse hole of the cannon
is counterbored as shown and a small hole is drilled at one side
to receive a small piece of copper wire, E. The wood screw, C,
nearly touches E and is connected to one binding post of the
induction coil. The other binding post is connected with the wood
screw, D, which conducts the current into the cannon, and also
holds the pieces of wood, A and B, in position.

When the cannon is loaded, a small quantity of powder is placed in
the counterbore, and the spark between C and E ignites this and
discharges the cannon. A cannon may be fired from a distance in
this way, and as there is no danger of any spark remaining after
the current is shut off, it is safer than the ordinary cannon
which is fired by means of a fuse.
--Contributed by Henry Peck, Big Rapids, Mich.



** Simple Electric Lock [60]

The illustration shows an automatic lock operated by electricity,
requiring a strong magnet, but no weights or strings, which
greatly simplifies the device over many others of the kind.

[Illustration: Lock Operated by a Magnet]

The weight of the long arm, L, is just a trifle greater than the
combined weights of the short arms, A and S. The fulcrum of the
lever is at C, where there is a staple. The lever swings on one
arm of the staple and the other arm is so placed that when the
lever is in an upright position, with the long arm at L', it will
not fall because of its greater weight but stays in the position
shown. The purpose of this is to leave the short arm, A, when in
position at A', within the reach of the magnet. Arm L rests on an
L-shaped hook, H; in this position the door is locked.

To unlock the door, press the button, B. The momentum acquired
from the magnet by the short arms, A and S, is sufficient to move
the long arm up to the position of L'. To lock the door, press the
button and the momentum acquired from the magnet by the short
arms, now at A' and S', is sufficient to move the long arm down
from L' to the position at L.
--Contributed by Benjamin Kubelsky, Chicago.



** Direct-Connected Reverse for Small Motors [60]

A simple reverse for small motors can be attached directly to the
motor as shown in Fig. 1. Fig. 2 shows the construction of the
reverse block: A is a strip of walnut 5/8 in. square and 3/8 in.
thick with strips of brass or copper (BB) attached as shown. Holes
(CC) are drilled for the wire connections and they must be flush
with the surface of the block. A hole for a 1/2 in. screw is bored
in the block. In Fig. 1, D is a thin strip of walnut or other
dense, hard wood fitted to the binding posts of the brush holders,
to receive the screw in the center.

Before putting the reverse block on the motor, remove all the
connections between the lower binding posts and the brush holders
and connect both ends of the field coil to the lower posts. Bend
the strips BB (Fig. 2) to the proper position to make a wiping
contact with the nuts holding the strip of wood D, Fig. 1. Put the
screw in tight

[Illustration: Direct-Connected Reverse]

enough to make the block turn a little hard. Connect as shown in
the illustration. To reverse, turn the block so the strips change
connections and the motor will do the rest.
--Contributed by Joseph B. Keil, Marion, Ohio.



** A Handy Ice Chisel [61]

Fishing through the ice is great sport, but cutting the first
holes preparatory to setting the lines is not always an easy task.
The ice chisel here described will be found very handy, and may be
made at very slight expense.

In the top of an old ax-head drill a 9/16-in. hole, and then tap
it for a 3/8-in. gas-pipe, about 18 in. long. Thread the other end
of the pipe, and screw on

[Illustration: Combination Ax and Ice Chisel]

an old snow-shovel handle. When ready for use, screw the two
pieces together and you have your chisel complete.

A short ax-handle may be included in the outfit. When the holes
are finished and your lines set, unscrew the pipe from the head of
the ax, put in the handle, and your ax is ready to cut the wood to
keep your fire going.
--Contributed by C. J. Rand, West Somerville, Mass.



** More Uses for Pipe Fittings [61]

It would seem that the number of useful articles that can be made
from pipes and fittings is unlimited. The sketch shows two more
that may be added to the list. A and B are front and side views of
a lamp-screen, and C is a dumbbell. The lamp shade is particularly
useful for shading the eyes when reading or writing and, if
enameled white on the concave side, makes an excellent reflector
for drawing at night, or for microscopic work.

The standard and base, consisting of an ordinary pipe flange
bushed down to receive the upright nipple, are enameled a jet
black, and if the device is to be used on a polished table, a
piece of

[Illustration: Lamp Shade and Dumbbell]

felt should be glued to the bottom. A good way to hold the fan in
the nipple is to use a small wedge.

The dumbbells are made of short pieces of 3/4-in. pipe with
1-2-in. couplings fastened to each end by pouring melted lead in
the space between the pipes and the couplings. The appearance is
greatly improved by enameling black, and if desired the handles
may be covered with leather.
--Contributed by C. E. Warren, M. D., North Easton, Mass.



** Sealing-Wax Bent While Cold [61]

If a piece of sealing-wax is supported in a horizontal position by
one end, as shown at A in the sketch, it will gradually bend to
the shape indicated by the dotted lines B. To attempt bending it
with the hands would result in breaking it unless a steady
pressure were applied for a long time. This peculiar property is
also found in ice.

[Illustration: Bending Cold Sealing-Wax]



** Homemade Pottery Kiln [62]

A small kiln for baking clay figures may be built at a cost of $1.
The following shows the general plan of such a kiln which has
stood the test of 200 firings, and which is good for any work
requiring less than 1400° C.

Get an iron pail about 1 ft. high by 1 ft. across, with a cover.
Any old pail which is thick enough will do, while a new one will
cost about 80 cents. In the bottom of this cut a 2-in. round hole
and close it with a cork or wood plug, A, Fig. 1, which shall
project at least 2 in. inside the pail. Make a cylindrical core of
wood, B, Fig. 1, 8 in. long and 8 in. across. Make a

[Illustration: Homemade Pottery Kiln]

mixture of clay, 60%; sand, 15%; and graphite, 25%, kneading
thoroughly in water to a good molding consistency. Line the pail,
bottom and sides, with heavy paper and cover the core with same.
Now pack the bottom of the pail thoroughly with a 2-in. layer of
the clay mixture, and on it set the paper wrapped core, carefully
centering it. The 2 in. of space between the core and the sides of
the pail all around is to be filled with clay, C, as is shown in
the sketch, using a little at a time and packing it very tight. In
like manner make the cover of the kiln, cutting the hole a little
smaller, about 1 in. At the edge or rim of the cover encircle a
2-in. strip of sheet iron, E, Fig. 2, to hold the clay mixture, C.
Set aside for a few days until well dried.

While these are drying you may be making a muffle, if there is to
be any glazing done. This is a clay cylinder (Fig. 3) with false
top and bottom, in which the pottery to be glazed is protected
from any smoke or dust. It is placed inside the kiln, setting on
any convenient blocks which will place it midway. The walls of the
muffle should be about 1/2 in. thick, and the dimensions should
allow at least 1 in. of space all around for the passage of heat
between it and the walls of the kiln. By the time the clay of the
kiln is well dried, it will be found that it has all shrunk away
from the iron about 3/8 in. After removing all the paper, pack
this space-top, bottom and sides with moist ground asbestos. If
the cover of the pail has no rim, it may be fastened to the
asbestos and clay lining by punching a few holes, passing wire
nails through and clinching them. Fit all the parts together
snugly, take out the plugs in the top and bottom, and your kiln is
ready for business. The handle of the pail will be convenient for
moving it about, and it can be set on three bricks or some more
elaborate support, as dictated by fancy and expense.

The temperature required for baking earthenware is 1250
degrees--1310 degrees, C.,; hotel china, 1330 degrees; hard
porcelain, 1390 degrees-1410 degrees. These temperatures can not
be obtained in the above kiln by means of the ordinary Bunsen
burner. If will be necessary either to buy the largest size
Bunsen, or make one yourself, if you have the materials. If you
can get a cone which can be screwed into an inch pipe, file the
opening of the cone to 1/16 in. diameter, and jacket the whole
with a 2-1/2-in. pipe. The flame end of this burner tube should be
about 4-1/2 in. above the cone opening and should be covered with
gauze to prevent flame from snapping back. When lighted, the point
of the blue flame, which is the hottest part, should be just in
the hole in the bottom of the kiln. Such a burner will be cheaply
made and will furnish a kiln temperature of 1400 degrees, but it
will burn a great deal of gas.

A plumber's torch of medium size will cost more in the beginning,
but will be cheaper in operation. Whatever burner is used, the
firing should be gradual, and with especial caution the first
time. By experiment you will find that a higher temperature is
obtained by placing a 1-in. pipe 2-ft. long over the lid hole as a
chimney. It would be still more effective to get another iron
pail, 2 in. wider than the kiln, and get a down draft by inverting
it over the kiln at whatever height proves most suitable. --G. L.
W.



** How to Make a Small Medical Induction Coil [63]

The coil to be described is 3-1/2 in., full length of iron core,
and 3/4 in. in diameter.

Procure a bundle of small iron wire, say 1/4 in. in diameter, and
cut it 3-1/2 in. long; bind neatly with coarse thread and file the
ends smooth (Fig. 1). This done, make two wood ends, 1-1/4 by
1-1/4 in. and 3/8 in. thick, and varnish. Bore holes in the center
of each so the core will fit in snugly and leave about 1/4 in.
projecting from each end (Fig. 1).

After finishing the core, shellac two layers of  thick paper over
it between the ends; let this dry thoroughly. Wind two layers of
bell magnet wire over this, allowing several inches of free wire
to come through a hole in the end. Cover with paper and shellac as
before. Wind about 1/8 in. of fine wire, such

[Illustration: Medical Induction Coil]

as used on telephone generators, around the coil, leaving long
terminals. Soak the whole in melted paraffin and let cool; bind
tightly with black silk.

The vibrator is made of a piece of thin tin to which is soldered
the head of an iron screw and on the other side a small piece of
platinum, which can be taken from an old electric bell (Fig. 2).

Of course, a regulator must be had for the vibrator; this can be
accomplished by bending a stout piece of copper wire as shown. The
connections and the base for setting up are shown in the figures.
--Contributed by J. T. R., Washington, D. C.



** Mechanical Trick With Cards [63]

The following mechanical card trick is easy to prepare and simple
to perform:

First, procure a new deck, and divide it into two piles, one
containing the red cards and the other the black ones, all cards
facing the same way. Take the red cards, square them up and place
in a vise. Then, with a plane, plane off the upper right hand
corner and lower left hand corner, as in Fig. 1, about 1/16 in.

Then take the black cards, square them up, and plane off about
1/16 in. on the upper left hand corner and lower right hand
corner, as in Fig. 2.

Next restore all the cards to one pack, taking care to have the
first card red, the next black, and so on, every alternate card
being the same color. Bend the pack so as to give some spring to
the cards, and by holding one thumb on the upper left-hand corner

[Illustration: Card Trick]

all the cards will appear red to the audience; place thumb in the
center at top of pack and they will appear mixed, red and black;
with thumb on upper right-hand corner all cards appear black. You
can display either color called for.
--Contributed by Ralph Gingrich, Chicago.



** How to Make a Rain Gauge [64]

An accurate rain gauge may be easily constructed from galvanized
iron, as shown in the sketch herewith. The funnel, A, overlaps and
rests on the body, B, and discharges into the tube, C, the area of
which is one-tenth that of the top of the funnel. The depth of the
water in C is thus ten times the actual rainfall, so that by
measuring it with a stick marked off in tenths of an inch, we
obtain the result in hundredths of an inch.

A good size to make the rain gauge is as follows: A, 8 in.
diameter; C, 2.53 in. ; length of C, about 20 in. It should be
placed in an exposed location, so that no inaccuracy will occur
from wind currents. To find the fall of snow, pour a known
quantity

[Illustration: Rain Gauge]

of warm water on the snow contained in the funnel and deduct the
quantity poured in from the total amount in the tube.
--Contributed by Thurston Hendrickson, Long Branch, N.J.



** How to Make an Aquarium [64]

In making an aquarium, the first thing to decide on is the size.
It is well not to attempt building a very large one, as the
difficulties increase with the size. A good size is 12 by 12 by 20
in., and this is inexpensive to build.

First buy one length of 3/4 by 1/8-in. angle iron for the frame,
F, Fig. 1. This can be obtained at any steel shop and should cost
about 20 cents. All the horizontal pieces, B, should be beveled 45
degrees at the ends and drilled for 3/16 in. stove bolts. The
beveling may be done by roughing out with a hacksaw and finishing
with a file. After all the pieces are cut and beveled they should
be drilled at the ends for the 3/16-in. stove bolts, C. Drill all
the horizontal pieces, B, first and then mark the holes on the
upright pieces, A, through the holes already drilled, thus making
all the holes coincide. Mark the ends of each piece with a figure
or letter, so that when they are assembled, the same ends will
come together again. The upright pieces, A, should be countersunk
as shown in the detail, and then the frame is ready to assemble.

After the frame has been assembled take it to glazier and have a
bottom made of skylight glass, and sides and ends of double-thick
window glass. The bottom glass should be a good fit, but the sides
and ends should be made slightly shorter to allow the cement, E,
to form a dovetail joint as shown. When the glass is put in the
frame a space, D, will be found between the glass and the
horizontal pieces, B, of the frame. If this were allowed to remain
the pressure of the water would spring the glass and cause a leak
at E; so it is filled up with plaster of paris.

The cement, E, is made as follows: Take 1 gill of plaster of
paris, 1 gill of litharge, 1 gill of fine white sand, and 1/3 of a
gill of finely powdered rosin. Mix well and add boiled linseed oil
and turpentine until as thick as putty. Let

[Illustration: Detail of Aquarium Frame]

the cement dry three or four days before putting any water in the
aquarium.

In choosing stock for the aquarium it should be remembered that a
sufficient quantity of vegetable life is required to furnish
oxygen for the fish. In a well balanced aquarium the water
requires renewal only two or three times a year. It is well to
have an excess of plants and a number of snails, as the snails
will devour all the decaying vegetable matter which would
otherwise poison the water and kill the fish.

[Illustration: Aquarium Finished]

If desired, a centerpiece (A, Fig. 2) can be made of colored
stones held together by cement, and an inverted jar can be
supported in the position shown at B. If the mouth of the jar is
below the surface of the water it will stay filled and allow the
fish to swim up inside as shown. Some washed pebbles or gravel
should be placed on the bottom, and, if desired, a few Chinese
lilies or other plants may be placed on the centerpiece.



** Homemade Pneumatic Lock [65]

Mount an old bicycle hand-pump, A, on the door by means of a metal
plate, B, having a swinging connection at C. Fasten the lever, D,
to the door knob, and make a hinge connection with the pump by
means of a piece of sheet

[Illustration: Pneumatic Door-Opener]

brass, E, soldered to the end of the cylinder. All this apparatus
is on the inside of the door and is connected by a small rubber
tube, F, to a secret mouthpiece placed at some convenient
location. A small piece of spring brass, screwed to the door
frame, will open the door about 1/2 in. when the operator blows in
the mouthpiece, or if the door is within reach of the mouthpiece,
the operator may push the door at the same time that he blows,
thus doing away with the spring, which is only used to keep the
door from relocking.

One way of making the air connection with the outside is to bend
the tube F around and stick it through the keyhole. Few burglars
would ever think to blow in the keyhole.
--Contributed by Orton E. White, Buffalo, N. Y.



** A Homemade Water Motor [66]
By MRS. PAUL S. WINTER

In these days of modern improvements, most houses are equipped
with a washing machine, and the question that arises in the mind
of the householder is how to furnish the power to run it
economically. I referred this question to my husband, with the
result that he built a motor which proved so very satisfactory
that I prevailed upon him to give the readers of Amateur Mechanics
a description of it, hoping it may solve the same question for
them.

A motor of this type will develop about 1/2 hp. with a water
pressure of 70 lb. The power developed is correspondingly
increased or decreased as the pressure exceeds or falls below
this. In the latter case the power may be increased by using a
smaller pulley. Fig. 1 is the motor with one side removed, showing
the paddle-wheel in position; Fig. 2 is an end view; Fig. 3 shows
one of the paddles, and Fig. 4 shows the method of shaping the
paddles. To make the frame, several lengths of scantling 3 in.
wide by 1 in. thick (preferably of hard wood) are required. Cut
two of them 4 ft. long, to form the main supports of the frame,
AA, Fig. 1 ; another, 2 ft. 6 in. long, for the top, B, Fig. 1;
another, 26 in. long, to form the slanting part, C, Fig. 1; and
another, D, approximately 1 ft., according to the slant given C.
After nailing these together as shown in the illustration, nail
two short strips on each side of the outlet, as at E, to keep the
frame from spreading.

Cut two pieces 30 in. long. Lay these on the sides of the frame
with their center lines along the line FF, which is 15 in. from
the outside top of the frame. They are shown in Fig. 2 at GG. Do
not fasten these boards now, but mark their position on the frame.
Two short boards 1 in. wide

[Illustration: Detail of Homemade Waterwheel]

by 1 in. thick (HH, Fig. 2) and another 1 in. by 1-1/2 in. (I,
Fig. 2) form a substantial base.

Cut the wheel from sheet iron 1/16 in. thick, 24 in. in diameter.
This can be done roughly with hammer and chisel and then smoothed
up on an emery wheel, after which cut 24 radial slots 3/4 in. deep
on its circumference by means of a hacksaw. On each side of the
wheel at the center fasten a rectangular piece of 1/4-in. iron 3
by 4 in. and secure it to the wheel by means of four rivets; after
which drill a 5/8 in. hole through the exact center of the wheel.

Cut 24 pieces of 1/32-in. iron, 1-1/2 by 2-1/2 in. These are the
paddles. Shape them by placing one end over a section of 1-in.
pipe, and hammer bowl shaped with the peen of a hammer, as shown
in Fig. 4. Then cut them into the shape shown in Fig. 3 and bend
the tapered end in along the lines JJ, after which place them in
the slots of the wheel and bend the sides over to clamp the wheel.
Drill 1/8-in. holes through the wheel and sides of the paddles and
rivet paddles in place. Next secure a 5/8-in. steel shaft 12 in.
long to the wheel about 8 in. from one end by means of a key. This
is done by cutting a groove in the shaft and a corresponding
groove in the wheel and fitting in a piece of metal in order to
secure the wheel from turning independently of the shaft. Procure
two collars or round pieces of brass (KK, Fig. 2) with a 5/8-in.
hole through them, and fasten these to the shaft by means of set
screws to prevent it from moving lengthwise.

Make the nozzle by taking a piece of 1/2-in. galvanized pipe 3-1/2
in. long and filling it with babbitt metal; then drill a 3/16-in.
hole through its center. Make this hole conical, tapering from
3/16 in. to a full 1/2 in. This is best done by using a square
taper reamer. Then place the nozzle in the position shown in Fig.
1, which allows the stream of water to strike the buckets full in
the center when they reach the position farthest to the right.
Take the side pieces, GG, and drill a 1-in. hole through their
sides centrally, and a 1/4-in. hole from the tops to the 1-in.
holes. Fasten them in their proper position, with the wheel and
shaft in place, the shaft projecting through the holes just
mentioned. Now block the wheel; that is, fasten it by means of
wedges or blocks of wood until the shaft is exactly in the center
of the inch holes in the side pieces. Cut four disks of cardboard
to slip over the shaft and large enough to cover the inch holes.
Two of these are to be inside and two outside of the frames (one
to bear against each side of each crosspiece). Fasten these to the
crosspieces by means of tacks to hold them securely. Pour melted
babbitt metal into the 1/4-in. hole to form the bearings. When it
has cooled, remove the cardboard, take down the crosspieces, and
drill a 1/8-in. hole from the top of the crosspieces through the
babbitt for an oil-hole.

Secure sufficient sheet zinc to cover the sides of the frame. Cut
the zinc to the same shape as the frame and let it extend down to
the crosspieces EE. Tack one side on. (It is well to tack strips
of heavy cloth--burlap will do--along the edges under the zinc to
form a water-tight joint.) Fasten the crosspiece over the zinc in
its proper position. Drill a hole through the zinc, using the hole
in the crosspiece as a guide. Then put the wheel in a central
position in the frame, tack the other side piece of zinc in place
and put the other crosspiece in place. Place the two collars
mentioned before on the shaft, and fasten so as to bear against
the crosspieces, in order to prevent the wheel and shaft from
moving sidewise. If the bearings are now oiled, the shaft should
turn easily and smoothly. Fasten a pulley 4 or 6 in. in diameter
to the longest arm of the shaft.

Connect the nozzle to a water faucet by means of a piece of hose;
place the outlet over a drain, and belt the motor direct to the
washing-machine, sewing machine, ice-cream freezer, drill press,
dynamo or any other machinery requiring not more than 1/2 hp.

This motor has been in use in our house for two years in all of
the above ways, and has never once failed to give perfect
satisfaction. It is obvious that, had the wheel and paddles been
made of brass, it would be more durable, but as it would have cost
several times as much, it is a question whether it would be more
economical in the end. If sheet-iron is used, a coat of heavy
paint would prevent rust and therefore prolong the life of the
motor. The motor will soon pay for itself in the saving of laundry
bills. We used to spend $1 a month to have just my husband's
overalls done at the laundry, but now I put them in the machine,
start the motor, and leave them for an hour or so. At the end of
this time they are perfectly clean, and I have noticed that they
wear twice as long as when I sent them to the laundry.



** How to Make Silhouettes [68]

Photography in all branches is truly a most absorbing occupation.
Each of us who has a camera is constantly experimenting, and
everyone of us is delighted when something new is suggested for
such experiments.

[Illustration: Making a Silhouette with the Camera]

To use a camera in making silhouettes select a window facing north
if possible, or if used only at times when the sun is not on it,
any window will do, says the Photographic Times. Raise the window
shade half way, remove any white curtains there may be, and in the
center of the lower pane of glass paste by the four corners a
sheet of tissue paper that is perfectly smooth and quite thick, as
shown in the sketch at B. Darken the rest of the window, shutting
out all light from above and the sides. Place a chair so that
after being seated the head of the subject will come before the
center of the tissue paper, and as near to it as possible, and
when looking straight before him his face will be in clear profile
to the camera.

Draw the shades of all other windows in the room. Focus the camera
carefully, getting a sharp outline of the profile on the screen.
Do not stop down the lens, as this makes long exposure necessary,
and the subject may move. Correct exposure depends, of course, on
the lens, light and the plate. But remember that a black and white
negative is wanted with as little detail in the features as
possible. The best plate to use is a very slow one, or what is
called a process plate.

[Illustration: Sample Silhouette]

In developing get all possible density in the high lights, without
detail in the face, and without fog. Printing is best done on
contrasty development paper with developer not too strong.

The ideal silhouette print is a perfectly black profile on a white
ground. With a piece of black paper, any shape in stopping off
print may be made as shown at C in the sketch.



** How to Make a Galvanoscope [68]

A galvanoscope for detecting small currents of electricity can be
made from a coil of wire, A; a glass tube, B, full of water; a
core, C; and a base, D, with binding posts as shown. The core C,
which is made of iron and cork, is a trifle lighter than the water
it displaces and will therefore normally remain in the top of the
tube; but as soon as a current of electricity passes through the
coil, the core is drawn down out of sight. The current required is
very small, as the core is so nearly balanced that the least
attraction will cause it to sink.

The glass tube may be a test tube, as shown in Fig. 2, or an empty
developer tube. If one has neither a test tube nor developer tube,
an empty pill bottle may be used. The washers at the ends of the
coil can be made of fiber, hard rubber, or wood; or can be taken
from an old magnet. The base may be made of wood or any other
insulating material and should have four short legs on the bottom.
Make the coil of single-covered wire about No. 18 and connect ends
to binding posts as shown in Fig. 2.

The core is made by pushing a small nail through a piece of cork.
It should be made so that it will rise slowly when placed under
water. Some filing may be necessary to get the weight just right,
but it should be remembered that the buoyancy of the core can be
adjusted after the parts are assembled, by pressing the cork in
the bottom of the test tube. This causes compression in the water
so that some is forced into the upper cork, reducing its
displacement and causing it to sink. The lower cork is then slowly
withdrawn, by twisting, until the core slowly rises.

[Illustration: Galvanoscope]

The instrument will then be adjusted ready for use. Connect the
binding posts to a single cell of battery--any kind will do, as a
slight current will answer. On completing

[Illustration: Interior View]

the circuit the core will descend; or put in a switch or push
button on one of the battery wires. If the button be concealed
where the operator can reach it, the core will obey his command to
rise or fall, according to his control of the current. This is a
mysterious looking instrument, the core being moved without
visible connection to any other part.



** Lubricating Sheet Metal [69]

To lubricate sheet metal mix 1 qt. whale oil, 1 lb. white lead, 1
pt. water and 3 oz. finest graphite. Apply with a brush before the
metal enters the dies.



** An Optical Top [69]

One of the latest optical delusions, and one not easy to explain,
is Benham's color top. Cut out the black and white disk shown in
the figure, and paste on a piece of stiff cardboard. Trim the
edges of the cardboard to match the shape of the disk, and make a
pinhole in the center. Cut the pin in half and push it through
from the under side until the head of the pin touches the
cardboard. Spin slowly in a strong light and some of the lines
will appear colored. The colors appear different to different
people, and are changed by reversing the rotation.

[Illustration: An Optical Top]



** Card Trick with a Tapered Deck [70]

Another simple trick to perform but one not easily detected, is
executed by using a tapered deck of cards as shown in Fig. 1. A
cheap deck of cards is evened up square, fastened in a vise and
planed along the edge in such a manner that all the pack will be
tapered about 1/16 in. This taper is exaggerated in the
illustration which shows

[Illustration: Cards from a Tapered Deck]

one card that has been turned end for end.

It is evident that any card reversed in this way can be easily
separated from the other cards in the pack, which makes it
possible to perform the following trick: The performer spreads the
cards out, fan-like, and asks an observer to withdraw a card,
which is then replaced in any part of the pack. After thoroughly
shuffling the cards the performer then holds the deck in both
hands behind his back and pronouncing a few magic words, produces
the card selected in one hand and the rest of the pack in the
other. This is accomplished by simply turning the deck end for end
while the observer is looking at his card, thus bringing the wide
end of the selected card at the narrow end of the pack when it is
replaced. The hands are placed behind the pack for a double
purpose, as the feat then seems more marvelous and the observers
are not allowed to see how it is done.

In prize games, players having the same score are frequently
called upon to cut for low to determine which shall be the winner,
but a fairer way is to cut for high as a person familiar with the
trick shown in Fig. 2 can cut the cards at the ace, deuce, or
three spot, nearly every time, especially if the deck is a new
one. This is done by simply pressing on the top of the deck as
shown, before cutting, thus causing the increased ink surface of
the high cards to adhere to the adjacent ones. A little practice
will soon enable one to cut low nearly every time, but the cards
must be grasped lightly and the experiment should be performed
with a new deck to obtain successful results.
--Contributed by D.B.L., Chicago.



** A Constant-Pressure Hydrogen Generator [70]

By fitting three bottles, A, B, C, with rubber stoppers and
connecting with glass tubes as shown in the sketch, hydrogen or
other gases produced in a similar manner may be generated under
constant pressure. In making hydrogen, bottle B is partly filled
with zinc nodules formed by slowly pouring melted zinc into water.
Hydrochloric acid is then poured in the small funnel, thus partly
filling bottles A and C. When the acid rising from C comes in
contact with the zinc, hydrogen gas is generated and fills bottle
B. The gas continues to generate until the pressure is sufficient
to force the acid back down the tube into bottle C, when the
action ceases. As fast as the gas is used the acid rises in the
tube and generates more, thus keeping the pressure nearly
constant, the pressure depending on the difference between the
levels of the acid in bottle A and bottle B. As this device is
easily upset, a ring-stand should be used to prevent its being
broken, or if it is to be a permanent apparatus it may be mounted
on a substantial wooden base. This apparatus may also be used for
preparing acetylene gas or almost any gas which requires a mixture
of a solid and liquid in its preparation.
--Contributed by C. S. J., Detroit.



** Restoring Tone to a Cracked Bell [71]

Many a bell with a deadened tone due to a cracked rim, can be
given its original clear ringing sound by sawing out the crack
with a common hacksaw. Make the saw cut along the line of the
crack. The opening caused by the saw will allow the free vibration
of the metal.
--Contributed by F. W. Bently, Jr., Huron, S. Dak.



** How to Make a Paper Phonograph Horn [71]

Secure a piece of tubing about 1-3/4 in. long that will fit the
connection to the reproducer, and wrap a quantity of heavy thread
around one end as shown in the enlarged sketch A, Fig. 1. Form a
cone of heavy paper, 9 in. long and 3 in. in diameter, at the
larger end with the smaller end to fit the diameter of the tube A,
making it three-ply thick and gluing the layers together. Attach
this cone on the tube A where the thread has been wrapped with
glue, as shown in Fig. 2. Fig. 2 is also an enlarged sketch. Make
ten pieces about 1 ft. 10 in. in length and 3 in. wide from the
thin boards of a biscuit or cracker box. Cut an arc of a circle in
them on a radius of 2 ft. (Fig. 3). Make a 10-sided stick, 12 in.
long, that will fit loosely in the tube A, to which nail the 10
pieces as shown in Fig. 4, connecting the bottom by cross pieces,
using care to keep them at equal distances apart and in a circle
whose diameter is about 2 ft.

[Illustration: Detail of Phonograph Horn]

The cone is placed over the stick as shown by the dotted lines in
Fig. 4 and temporarily fastened in position. Cut out paper
sections (Fig. 5) that will cover each space between the 10
pieces, allowing 1 in. on one side and the top, in which to cut
slits that will form pieces to overlap the next section and to
attach with glue. Fasten the sections all around in like manner.
The next course is put on in strips overlapping as shown at B,
Fig. 6. Finish by putting on sections in the same way as the first
course, making it three-ply thick. Remove the form, trim to suit
and glue a piece of paper over the edge. When the glue is
thoroughly hardened, put on two coats of white and one of blue
paint, shading it to suit and striping it with gold bronze.



** How to Make a Hygrometer [71]

A homemade hygrometer, for determining the degree of moisture in
the atmosphere, is shown in the accompanying sketch and consists
of a board, A, with a nail at each end to hold the silk thread B.
A second piece of silk thread, C, is tied to the center of B and
connects with an indicating hand or pointer supported by the
bracket D. The axle on which the pointer revolves consists of a
piece of round wood, about the size of a lead-pencil, with a pin
driven in each end. A piece of tin, E, is cut V-shaped at each end
and bent up at the ends to form bearings for the pins. The silk
thread C is fastened to the wooden axle and is wrapped one or two
turns around it, so that when

[Illustration: The Hygrometer]

the thread is pulled the pointer will move on the scale. It will
be noticed that the thread B is not perfectly straight, but bends
toward D. For this reason a very small shrinkage of B, such as
occurs when the atmosphere is dry, will cause an increased
movement of C, which will be further increased in the movement of
the pointer. An instrument of this kind is very interesting and
costs nothing to make.
--Contributed by Reader, Denver.



** The Protection of a Spring Lock [72]

After shutting the front door and hearing the spring lock snap
into its socket, most people go off with a childlike faith in the
safety of their goods and chattels. But the cold fact is that
there is scarcely any locking device which affords less protection
than the ordinary spring lock. It is the simplest thing in the
world for a sneak thief to slip a thin knife between the
door-casing and the strip, push back the bolt, and walk in.

Fortunately, it is equally easy to block that trick. Take a narrow
piece of tin 3 or 4 in. long, bend it at right angles throughout
its length, and tack it firmly in the angle between the casing and
strip, so as to make it impossible to reach the bolt without
tearing off the strip.

Another way is to drive nails through the strip at intervals of
half an inch, enough to protect the bolt from being meddled with.



** A Controller and Reverse for a Battery Motor [72]

Secure a cigar or starch box and use to make the base, B. Two
wood-base switches, S S, are cut off a little past the center and
fastened to the base with a piece of wood between them. The upper
switch, S, is connected to different equal points on a coil of
wire, W, while the lower switch, S, is connected each point to a
battery, as shown. The reverse switch, R, is made from two brass
or copper strips fastened at the top to the base with screws and
joined together by a piece of hard rubber or wood with a small
handle attached. Connect wires A to the armature and wires F to
the field of the motor. By this arrangement one, two or three and
so on up until all the battery cells are used and different points
of resistance secured on the coil of wire. The reverse lever when
moved from right to left, or left to right, changes the direction
of the armature in the motor from one way to the other.
--Contributed by J. Fremont Hilscher, Jr., West St. Paul, Minn.

[Illustration: Motor Reverse and Controller]



** How to Build a Grape Arbor [73]

A grape arbor made of white pine, put together as shown in the
sketch, will last for several years. The 2 by

[Illustration: Grape-Arbor Trellis]

4-in. posts, A, are 7 ft. long. The feet, B, are made 2 by 4 in.,
4 ft. long, and rest on a brick placed under each end.



** How to Make a Toy Steam Engine [73]

A toy engine can be easily made from old implements which can be
found in nearly every house.

[Illustration: Toy Steam Engine Assembled]

The cylinder A, Fig. 1, is an old bicycle pump, cut in half. The
steam chest D, is part of the piston tube of the same pump, the
other parts being used for the bearing B, and the crank bearing C.
The flywheel Q can be any small-sized iron wheel; either an old
sewing-machine wheel, pulley wheel, or anything available. We used
a wheel from an old high chair for our engine. If the bore in the
wheel is too large for the shaft, it may be bushed with a piece of
hard wood. The shaft is made of heavy steel wire, the size of the
hole in the bearing B.

[Illustration: Valve Motion and Construction of Piston]

The base is made of wood, and has two wood blocks, H and K, 3/8
in. thick, to support bearing B, and valve crank S, which is made
of tin. The hose E connects to the boiler, which will be described
later. The clips FF are soldered to the cylinder and nailed to the
base, and the bearing B is fastened by staples.

The valve motion is shown in Figs. 2 and 3. In Fig. 2 the steam is
entering the cylinder, and in Fig. 3 the valve B has closed the
steam inlet and opened the exhaust, thus allowing the steam in the
cylinder to escape.

The piston is made of a stove bolt, E, Fig. 2, with two washers,
FF, and a cylindrical piece of hard wood, G. This is wound with
soft string, as shown in Fig. 3, and saturated with thick oil. A
slot is cut in the end of the bolt E, to receive the connecting
rod H. The valve B is made of an old bicycle spoke, C, with the
nut cut in half and filed down as shown, the space between the two
halves being filled with string and oiled.

The valve crank S, Fig. 1, is cut out of tin, or galvanized iron,
and is moved by a small crank on the shaft. This crank should be
at right angles to the main crank.

[Illustration: Engine in Operation]

The boiler, Fig. 4, can be an old oil can, powder can, or a syrup
can with a tube soldered to it, and is connected to the engine by
a piece of rubber tubing. The heat from a small gas stove will
furnish steam fast enough to run the engine at high speed. This
engine was built by W. G. Schuh and A. J. Eustice, of Cuba, Wis.



** Writing with Electricity [74]

Soak a piece of white paper in a solution of potassium iodide and
water for about a minute and then lay it on a piece of sheet
metal. Connect the sheet metal with the negative or zinc side of a
battery and then, using the positive wire as a pen, write your
name or other inscription on the wet paper.

[Illustration: Electrolytic Writing]

The result will be brown lines on a white background.
--Contributed by Geo. W. Fry, San Jose, Cal.



** To Photograph a Man in a Bottle [74]

Neither a huge bottle nor a dwarfed man is necessary for this
process, as it is merely a trick of photography, and a very
amusing trick, at that.

First, photograph the person to be enclosed in the bottle against
a dark plain background and mark the exact position on the ground
glass. Let the exposure be just long enough to show the figure
distinctly. Then place an empty bottle against a dark background
and focus so as to have the outlines of the bottle enclose those
of the man. Let this exposure be about twice the length of the
first, and the desired result is obtained.



** A Musical Windmill [74]

Make two wheels out of tin. They may be of any size, but wheel A
must be larger than wheel B. On wheel A fasten two pieces of wood,
C, to cross in the center, and place a bell on the four ends, as
shown. The smaller wheel, B, must be separated from the other with
a round piece of wood or an old spool. Tie four buttons with split
rings to the smaller wheel, B. The blades on the wheels should be
bent opposite on one wheel from the others so as to make the
wheels turn in different directions. When turning, the buttons
will strike the bells and make them ring constantly.

[Illustration: Musical Windmill]



** Optical Illusions [74]

By giving the page a revolving or rinsing motion the three
circular figures printed on the next page appear to rotate. The
best effect will be produced by laying the book down flat on the
desk or table and revolving, first

[Illustration: Move These Figures Rapidly with a Rinsing Motion]

in one direction and then in the opposite direction, in such a way
that any given point on the page will describe a circle of about
1/2 in. diameter. Fig. 1 then appears to rotate in the same
direction as the revolution; Fig. 2 appears to revolve in the
opposite direction, and Fig. 3 appears to revolve sometimes in the
same direction and at other times in the opposite direction.

A curious effect can be produced with Fig. 1 by covering up Figs.
2 and 3 with a piece of plain paper and laying a coin or other
small object on the paper. If the vision is then concentrated on
the coin or other object while same is being revolved, Fig. 1 will
be seen to rotate.



** Barrel-Stave Hammock  [75]

A hammock made of barrel staves is more comfortable than one would
think, considering the nature of the material employed in making
it. Good smooth staves should be selected for this purpose, and if
one cares to go to little trouble a thorough sandpapering will
make a great improvement. Cut half circles out of each stave, as
shown at AA, and pass ropes around

[Illustration: Cheap and Comfortable]

the ends as shown at B. When finished the weight will then be
supported by four ropes at each end, which allows the use of small
sized ropes, such as clothes lines. A hammock of this kind may be
left out in the rain without injury.
--Contributed by H.G.M., St. Louis, Mo.



** A Singing Telephone [75]

Those who have not already tried the experiment may be interested
to know that a telephone may be made to sing by holding the
receiver about 1/16 in. from the transmitter, as shown in the
illustration. The experiment will

[Illustration: To Make a Telephone Sing]

work well on most telephones, but not on all.

When the receiver is placed in the position shown it acts like an
ordinary buzzer, and the function of the transmitter will then be
that of an interrupter. The slightest movement of the transmitter
diaphragm will cause an increased movement of the receiver
diaphragm. This in turn will act on the transmitter, thus setting
up sympathetic vibrations between the two, which accounts for the
sound.



** A Microscope Without a Lens [76]
By E. W. DAVIS

Nearly everyone has heard of the pin-hole camera, but the fact
that the same principle can be used to make a microscope, having a
magnifying power of 8 diameters (64 times) will perhaps be new to
some readers. To make this lensless microscope, procure a wooden
spool, A (a short spool, say 1/2 or 3/4 in. long, produces a
higher magnifying power), and enlarge the bore a little at one
end. Then blacken the inside with india ink and allow to dry. From
a piece of thin

[Illustration: Detail of Lensless Microscope]

transparent celluloid or mica, cut out a small disk, B, and fasten
to the end having the enlarged bore, by means of brads. On the
other end glue a piece of thin black cardboard, C, and at the
center, D, make a small hole with the point of a fine needle. It
is very important that the hole D should be very small, otherwise
the image will be blurred.

To use this microscope, place a small object on the transparent
disk, which may be moistened to make the object adhere, and look
through the hole D. It is necessary to have a strong light to get
good results and, as in all microscopes of any power, the object
should be of a transparent nature.

The principle on which this instrument works is illustrated in
Fig. 2. The apparent diameter of an object is inversely
proportional to its distance from the eye, i. e., if the distance
is reduced to one-half, the diameter will appear twice as large;
if the distance is reduced to one-third, the diameter will appear
three times as large, and so on. As the nearest distance at which
the average person can see an object clearly is about 6 in., it
follows that the diameter of an object 3/4 in. from the eye would
appear 8 times the normal size. The object would then be magnified
8 diameters, or 64 times. (The area would appear 64 times as
large.) But an object 3/4-in. from the eye appears so blurred that
none of the details are discernible, and it is for this reason
that the pin-hole is employed.

Viewed through this microscope, a fly's wing appears as large as a
person's hand, held at arm's length, and has the general
appearance shown in Fig. 3. The mother of vinegar examined in the
same way is seen to be swarming with a mass of wriggling little
worms, and may possibly cause the observer to abstain from all
salads forever after. An innocent-looking drop of water, in which
hay has been soaking for several days, reveals hundreds of little
infusoria, darting across the field in every direction. These and
hundreds of other interesting objects may be observed in this
little instrument, which costs little or nothing to make.



** How to Make a Telegraph Key and Sounder [76]

The sounder, Fig. 1, is made from an old electric-bell magnet, D,
fastened to a wooden base. The lever, A, can be made of brass and
the armature, C, is made of iron. The pivot, E, is made from a
wire nail and is soldered to A. It should be filed to a point at
each end so as to move freely in the bearings, B, which are pieces
of hard wood. The spring, H, is fastened at each end by pins, bent
as shown, and should not be too strong or the magnet will be
unable to move the armature.

[Illustration: SOUNDER-A. brass: B. wood: C. soft iron; DD. coils
wound with No. 26 wire: E. nail soldered on A; FF. binding posts:
H spring]

The stop, K, is a wire nail driven deep enough in the base to
leave about 1/8 in. between the armature and the magnet. The
binding posts, F, may be taken from old dry batteries and are
connected to the two wires from the magnet by wires run in grooves
cut in the base.

The base of the key, Fig. 2, is also made of wood and has two
wooden bearings, E, which are made to receive a pivot, similar to
the one used in the sounder. The lever of the key is made of brass
and has a hardwood knob, A, fastened near the end. A switch, D,
connects with the pivot at F and can be either made from sheet
brass, or taken from a small one-point switch. The binding posts
are like those of the sounder, and are connected to the contacts,
K, by wires run in grooves cut in the wood.

[Illustration: KEY-A. wood; B. brass or iron soldered to nail; C.
brass; D. brass: E. wood: F. connection of D to nail; HH. binding
posts]



** How to Make a Music Cabinet [77]

A neat music cabinet can be made as shown in the accompanying
sketch. Each side, AA, Fig. 1, is cut from a board about 36 in. in
length and 16 in. wide. Both are alike and can be cut from the
same pattern. As the front legs curve out a little the main body
of the boards AA should be 15 in. wide. The back, B, should be
about 22 in. long by 16 in. wide and set in between sides AA. Cut
the top, C, 16 in. long and 14-1/2 in. wide. The bottom must be
the same length as the top and 13-1/2 in. wide.

The door, D, can be made panel as shown, or a single piece, 16 in.
wide and about 20 in. long. All material used is to be made from
boards that will dress to 3/4 in. thick.

[Illustration: How to Make a Music Cabinet]

Shelving may be put in as shown in Fig. 2 and made from 1/4-in.
material. Make 12 cleats, E, 13-1/2 in. long, from a strip of wood
1/2 by 3/4 in., with a groove 1/4 by 1/4 in. cut in them. Fasten 6
cleats evenly spaced on the inside of each of the sides, AA, with
3/4-in. brads. This will give seven spaces for music and as the
shelves are removable two places can be made into one.



** Easily Made Wireless Coherer [77]

A good wireless coherer may be made with very little expense, the
only materials necessary being a glass tube, two corks: a
magnetized needle and a quantity of iron and silver filings. Push
a piece of wire through one cork and place in the bottom of the
tube, as shown in the sketch.

Pour in the filings and insert the top cork with the needle pushed
through

[Illustration: Detail of Coherer]

from above. The point of the needle should barely touch the
filings and by slightly agitating the tube the iron filings will
separate from the silver and cling to the magnetized needle, as
shown.

In operation, the device must stand on end and should be connected
in the circuit as shown in the sketch. When the electrical waves
strike the needle, the conductivity of the filings is established
and a click is heard in the receiver.
--Contributed by Carl Formhals, Garfield, Ill.



** One-Wire Telegraph Line [78]

The accompanying wiring diagram shows a telegraph system that
requires no switches and may be operated with open-circuit
batteries on a one-wire

[Illustration: Diagram of One-Wire Line]

line with ground connections at each end. Any telegraph set in
which the key makes double contact can be connected up in this
way.
--Contributed by R. A. Brown, Fairport, N. Y.



** How to Make a Water Rheostat [78]

A water rheostat may be made by fitting a brass tube with a cork,
through which a piece of wire is passed. The brass tube may be an
old bicycle hand pump, A (see sketch), filled with water. Pushing
the wire, B, down into the water increases the surface in contact,
and thus decreases the resistance. An apparatus of this kind is
suitable for regulating the current from an induction coil, when
the coil is not provided with a regulator, and by using a piece of
pipe instead of the tube, it can be used to regulate the speed of
a motor.

When the pipe is used, a piece of brass or copper rod should be
substituted for the wire, in order to increase the surface. Adding
salt to the water will decrease the resistance, and, when used
with a motor, will give a greater speed.
--Contributed by John Koehler, Ridgewood, N. J.

[Illustration: Diagram of One-Wire Line Water Rheostat]



** Electric Door-Opener [78]

A very convenient and efficient device for unlocking any door
fitted with a spring lock is shown in the accompanying sketches. A
fairly stiff spring, A, is connected by a flexible wire cord to
the knob B. The cord is also fastened to a lever, C, which is
pivoted at D and is released by a magnetic trigger, E, made from
the armature and magnet of an old electric bell.

When the circuit is completed by means of a secret contact device
outside the door, the magnet, F, pulls down the armature, which
releases the trigger and allows the spring to open the lock. If
there are metal numbers on the outside of the door they may be
used for the secret contact, if desired,

[Illustration: Apparatus Placed on Inside of Door]

but if there are no numbers on the door, a small contact-board may
be constructed by driving about 12 brass headed tacks into a thin
piece of wood and making connections at the back as shown in the
wiring diagram.

In this particular diagram the tacks numbered 1 and 7 are used for
unlocking the door, the others being connected with the
electric-bell circuit as indicated, for the purpose of giving an
alarm should anybody try to experiment with the secret contacts.
By means of a pocket knife or other metal article the operator can
let himself in at any time by connecting the tacks numbered 1 and
7, while a person not knowing the combination would be liable to
sound the alarm. Of course, the builder of this device may choose
a combination of his own and may thus prevent anybody else from
entering the door, even those who read this description.
--Contributed by Perry A. Borden, Gachville, N. B.

[Illustration: Wiring Diagram]



** How to Tighten a Curtain-Roller Spring [79]

A common table fork can be used to hold the little projection on
the end of a curtain roller for tightening the spring. Hold the
fork firmly with one hand while turning the roller with the other.
Do not let go of the fork until the little catches are set in
position to prevent the spring from turning, or else the fork may
be thrown off with dangerous force.



** Alarm Clock Chicken Feeder [79]

An automatic poultry feeder, which will discharge the necessary
amount of corn or other feed at any desired time, may be made by
using an alarm clock as shown in the sketch. A small wire trigger
rests on the winding key and supports the swinging bottom of the
food hopper by means of a piece of string which connects the two.
When the alarm goes off the trigger drops and allows the door to
open, thus discharging the contents of the hopper.

After the device has been in operation for some time the hens will
run to the feeder whenever the. bell rings.
--Contributed by Dr. H. A. Dobson, Washington, D. C.

[Illustration: Will Open or Close Circuit as Desired]



** Homemade Disk-Record Cabinet [79]

Select some boards that have a nice grain and about 1 in. thick
and 12-in. wide. Cut the end pieces each 36-in. long and trim down
the edges so as to make them 11-3/8 in. wide. The top board is
made 28-in. long and full 12-in. wide. The three shelves are cut
25-in. long and the edges trimmed so they will be 11-3/8 in. wide.
The distance between the bottom of the top board and the top of
the first shelf should be 3 in. Two drawers are fitted in this
space, as shown in Fig. 1. A series of grooves are cut 1/4 in.
wide,

[Illustration: Cabinet Holding 32 Records]

1/4 in. deep and 3/4 in. apart on one side of the top and bottom
shelves, as shown in Fig. 2, and on both sides of the middle
shelf. The shelves should be spaced 9-5/8 in. for 10-in. records
and 5-5/8 in. for 6-in. records. A neat scroll design is cut from
a board 25 in. long to fill up and finish the space below the
bottom shelf.
--Contributed by H. E. Mangold, Compton, Cal.



** A Battery Rheostat [80]

In a board 7 in. long and 5 in. wide bore holes about 1/4 in.
apart, in a semicircle 2 in. from the bottom, and cut notches in
top end to correspond with the holes. From a piece of brass a
switch, C, is cut with a knob soldered on at the end. Nails for
stops are placed at DD. Two binding-posts are placed in board at A
and B. With about 9 ft. of fine iron wire attach one end to the
bottom of post A and run through first hole and over in first
notch to back of board and then through second hole and over
second notch and so on until E is reached, where the other end of
wire is fastened. Connect switch to post B.
--Contributed by Edmund Kuhn, Jr., East Orange, N. J.

[Illustration: Battery Rheostat]



** Automatic Time Switch [80]

This device may be used to either open or close the circuit at any
desired time. An alarm clock is firmly fastened to a wooden
bracket and provided with a small wood or metal drum, A, to which
is fastened a cord, B. The other end of the cord is tied to the
switch handle so that when the alarm goes off the switch is either
opened or closed, depending on whether the cord is passed over
pulley C or pulley D.

When the cord is passed over pulley C, as shown in Fig. 1, the
circuit will be closed when the alarm goes off, but if it is
passed over D the circuit will be opened. Pulley D is fastened to
a piece of spring steel, E, which in operation is bent, as shown
by the dotted lines, thus causing the switch to snap open quickly
and prevent forming an arc.
--Contributed by Douglas Royer, Roanoke, Va.

[Illustration: Will Open or Close Circuit as Desired]



** How to Make a Rotary Pump [81]

[Illustration: Details of Rotary Pump]

A simple rotary pump is constructed on the principle of creating a
vacuum in a rubber tube and so causing water to rise to fill the
vacuum. Figs. 3, 4 and 5 show all the parts needed, excepting the
crank and tubing. The dimensions and description given are for a
minimum pump, but a larger one could be built in proportion.

Through the center of a block of wood 4 in. square and 7/8 in.
thick (A, Figs. 1, 2 and 3) saw a circular opening 2-7/8 in. in
diameter. On each side of this block cut a larger circle 3-1/4 in.
in diameter, having the same center as the first circle (Fig. 3).
Cut the last circles only 1/4 in. deep, leaving the first circle
in the form of a ridge or track 3/8 in. wide, against which the
rubber tubing, E, is compressed by wheels. Bore two 1/4 in. holes
(HH, Fig. 1) from the outside of the block to the edge of the
inner circle. Put the rubber tube, E, through one of these holes,
pass it around the track and out through the other hole. Notice
the break (S) in the track; this is necessary in order to place in
position the piece holding the wheels.

Fig. 4 shows the wheel-holder, B. Make it of hard wood 3-1/8 in.
long, 1 in. wide and a little less than 7/8 in. thick, so that it
will run freely between the sides (Fig. 5) when they are placed.
Cut two grooves, one in each end, 1 in. deep and 1/2 in. wide. In
these grooves place wheels, CC, to turn on pins of stout wire.
These wheels should be 3/4 in. in diameter. When placed in the
holder their centers must be exactly 2 in. apart, or so arranged
that the distance between the edge of the wheels and the track (K,
Fig. 1) is equal to the thickness of the tubing when pressed flat.
If the wheels fit too tightly, they will bind; it too loose, they
will let the air through. Bore a hole through the middle of the
wheel-holder and insert the crankpin, D, which should be about 1/2
in. in diameter. The crankpin should fit tightly; if necessary
drive a brad through to keep it from slipping.

In the sides (Fig. 5) bore a hole in the center of the crankpin to
run in loosely. Now put all these parts together, as shown in the
illustration. Do not fasten the sides too securely until you have
tried the device and are sure it will run smoothly. For the crank
a bent piece of stout wire or a nail will serve, though a small
iron wheel is better, as it gives steadiness to the motion. In
this case a handle must be attached to the rim of the wheel to
serve as a crank. The drive wheel from a broken-down eggbeater
will do nicely. For ease in handling the pump, a platform should
be added.

To use the pump, fill the tube with water and place the lower end
of the tube in a reservoir of water. Make a nozzle of the end of a
clay pipe stem for the other end of the tube. Then turn the crank
from left to right. The first wheel presses the air out of the
tube, creating a vacuum which is immediately filled with water.
Before the first wheel releases the tube at the top, the other
wheel has reached the bottom, this time pressing along the water
that was brought up by the first wheel. If the motion of the
wheels is regular, the pump will give a steady stream. Two feet of
1/4-in. tubing, costing 10 cents, is all the expense necessary.
--Contributed by Dan H. Hubbard, Idana, Kan.



** How to Make a Fire Screen [82]

[Illustration: FIG.2  Made of Strap Iron]

A screen which will not interfere with the radiation of the heat
from the fire, and will keep skirts and children safe can be made
at little expense out of some strap iron. The screen which is
shown in Fig. 1, stands 20 in. high from the base to the top
crosspiece and is made of 3/4 by 1/4-in. and 1/2 by 1/4-in. iron.
The top and bottom pieces marked AA, Fig. 1, are 3/4 by 1/4 in.
and are 30 in. long, bent at an angle to fit the fireplace 7 in.
from each end, as shown in Fig. 2. The three legs marked BBB, Fig.
1, are of the same size iron and each leg will take 34 in. of
material. In shaping the feet of these three pieces give them a
slight tendency to lean toward the fire or inside of screen, says
a correspondent in the Blacksmith and Wheelwright. In the two
cross bars 1 in. from each end, A in Fig. 2, mark for hole and 3
in. from that mark the next hole. Take the center of the bar, B,
15 in. from each end, and mark for a hole, and 3-1/2 in. on each
side mark again and 3-1/2 in. beyond each of these two, mark
again.

Mark the legs 2-3/4 in. from the bottom and 2 in. from the top and
after making rivet-holes rivet them to the cross bars, AA, Fig. 1.

Cut six pieces, 17-1/2 in. long and punch holes to fit and rivet
onto the remaining holes in cross bars, AA, Fig. 1. Clean it up
and give it a coat of black Japan or dead black.



** Trap for Small Animals [82]

This is a box trap with glass sides and back, the panes of glass
being held in place by brads placed on both sides. The animal does
not fear to enter the box, because he can see through it: when he
enters, however, and touches the bait the lid is released and,
dropping, shuts him in. This is one of the easiest traps to build
and is usually successful.

[Illustration: Trap]



** Homemade Grenet Battery [83]

Procure an ordinary carbon-zinc, sal-ammoniac battery and remove
the zinc rod. If the battery has been used before, it is better to
soak the carbon cylinder for a few hours to remove any remaining
crystals of sal-ammoniac from its pores.

The truncated, conical zinc required is known as a fuller's zinc
and can be bought at any electrical supply dealer's, or, it may be
cast in a sand mold from scrap zinc or the worn-out zinc rods from
sal-ammoniac batteries. It should be cast on the end of a piece of
No. 14 copper wire. Amalgamation is not necessary for the zinc one
buys, but if one casts his own zinc, it is necessary to amalgamate
it or coat it with mercury. This may be done as follows:

Dip a piece of rag in a diluted solution of sulphuric acid (water
16 parts, acid 1 part); rub the zinc well, at the same time
allowing a few drops of mercury to fall on a spot attacked by the
acid. The mercury will adhere, and if the rubbing is continued so
as to spread the mercury, it will cover the entire surface of the
zinc, giving it a bright, silvery appearance.

Next procure what is known as a wire connector. This is a piece of
copper tube about 1-1/2 in. long having two thumb screws, one on
each end on opposite sides (Fig. 2). The upper screw is to connect
the battery wire, the lower one to raise and lower the zinc. The
battery is now complete, and the solution (Fig. 1) must be
prepared. Proceed as follows:

In 32 oz. of water dissolve 4 oz. potassium bichromate. When the
bichromate has all dissolved, add slowly, stirring constantly, 4
oz. sulphuric acid. Do not add the acid too quickly or the heat
generated may break the vessel containing the solution. Then pour
the solution into the battery jar, until it is within 3 in. of the
top. Thread the wire holding the zinc through the porcelain
insulator of the carbon cylinder and also through the wire
connector. Pull the zinc up as far as it will go and tighten the
lower thumb screw so that it holds the wire secure. Place the
carbon in the jar. If the solution touches the zinc, some of it
should be poured out. To determine whether or not the zinc is
touched by the solution, take out the carbon and lower the zinc.
If it is wet, there is too much liquid in the jar. The battery is
now ready for use.

To cause a flow of electricity, lower the zinc until it almost
touches the bottom of the jar and connect an electric bell or
other electrical apparatus by means of wires to the two binding
posts.

This battery when first set up gives a current of about two volts.
It is useful for running induction coils, or small electric
motors. When through using the battery, raise the zinc and tighten
the lower thumb screw. This prevents the zinc wasting away when no
current is being used.
--Contributed by H. C. Meyer, Philadelphia.

[Illustration: Fig.1 Details of Homemade Battery]



** Door-Opener for Furnace [83]

The accompanying diagram shows an arrangement to open the coal
door of a furnace. When approaching the furnace with a shovelful
of coal it is usually necessary to rest the shovel on the top of
the ash door, while the coal door is being opened. With my device
it is only necessary to press the foot pedal, which opens the
door. After putting in the coal, pressing the pedal closes the
door. The pulley in the ceiling must be placed a little in front
of the door, in order to throw the door open after lifting it from
the catch. A large gate hinge is used to hold the pedal to the
floor.
--Contributed by Edward Whitney, Madison, Wis.

[Illustration: Furnace Door Opener]



** How to Make an Efficient Wireless Telegraph [84]
By GEORGE W. RICHARDSON

A simple but very efficient wireless telegraph may be constructed
at slight cost from the following description:

The sending apparatus consists of nothing but an induction coil
with a telegraph key inserted in the primary circuit, i. e., the
battery circuit. This apparatus may be purchased from any
electrical-supply house. The price of the coil depends upon its
size, and upon the size depends the distance signals can be
transmitted. If, however, one wishes to construct his own coil he
can make and use, with slight changes, the jump-spark coil
described elsewhere in this book. This coil, being a 1-in. coil,
will transmit nicely up to a distance of one mile; while a 12-in.
coil made on the same plan will transmit 20 miles or even more
under favorable conditions.

Change the coil described, as follows: Insert an ordinary
telegraph key in the battery circuit, and attach two small pieces
of wire with a brass ball on each, by inserting them in the
binding-posts of the coil as shown at B B". Of these two terminal
wires one is grounded to earth, while the other wire is sent aloft
and is called the aerial line. This constitutes all there is to
the sending apparatus.

Now for the receiving apparatus. In the earlier receiving
instruments a coherer was used, consisting of a glass tube about
1/8-in. diameter, in which were two silver pistons separated by
nickel and silver filings, in a partial vacuum. This receiver was
difficult of adjustment and slow in transmission. An instrument
much less complicated and inexpensive and which will work well can
be made thus:

Take a 5-cp. incandescent lamp and break off the tip at the dotted
line, as shown in Fig. 5. This can be done by giving the glass tip
or point a quick blow with a file or other thin edged piece of
metal. Then with a blow-torch heat the broken edges until red hot
and turn the edges in as seen in Fig. 6. Remove the carbon
filament in the lamp and bend the two small platinum wires so they
will point at each other as in Fig. 6, W W. Screw the lamp into an
ordinary wall socket which will serve as a base as in Fig. 7. Make
a solution of 1 part sulphuric acid to 4 parts of water, and fill
the lamp about two-thirds full (Fig. 7). This will make an
excellent receiver. It will be necessary to adjust the platinum
points, W W, to suit the distance the message is to be worked. For
a mile or less the points should be about 1/16 in. apart, and
closer for longer distances.

The tuning coil is simply a variable choking coil, made of No. 14
insulated copper wire wound on an iron core, as shown in Fig. 7.
After winding, carefully scrape the insulation from one side of
the coil, in a straight line from top to bottom, the full length
of the coil, uncovering just enough to allow a

[Illustration: Aerial]

good contact for the sliding piece. The tuning is done by sliding
the contact piece, which is made of light copper wire, along the
convolutions of the tuning coil until you can hear the signals.
The signals are heard in a telephone receiver, which is shown
connected in shunt across the binding posts of the lamp holder
with one or two cells of dry battery in circuit, Fig. 7.

[Illustration: Details]

The aerial line, No.6 stranded, is run from binding-post B through
the choking or tuning coil, and for best results should extend up
50 ft. in the air. To work a 20-mile distance the line should be
100 or 150 ft. above the ground. A good way is to erect a wooden
pole on a house or barn and carry the aerial wire to the top and
out to the end of a gaff or arm.

To the end of the aerial wire fasten a bunch of endless loops made
of about No. 14 magnet wire (bare or insulated), attaching both
ends to the leading or aerial wire. The aerial wire should not
come nearer than 1 ft. at any point to any metal which is
grounded.

Run a wire from the other binding post, A, to the ground and be
sure to make a good ground connection.

For simple experimental work on distances of 100 ft. only, an
ordinary automobile spark coil can be used in place of the more
elaborate coil, Figs. 1 to 4.

The above-mentioned instruments have no patents on them, and
anyone is at liberty to build and use them. The writer does not
claim to be the originator, but simply illustrates the above to
show that, after all, wireless is very simple when it is once
understood. The fundamental principles are that induction travels
at right angles, 90 degrees, to the direction of the current. For
an illustration, if a person standing on a bridge should drop a
pebble into the water below, after contact he would note circles
radiating out over the surface of the water. These circles, being
at right angles, 90 degrees, to the direction of the force that
caused the circles, are analogous to the flow of induction, and
hence the aerial line, being vertical, transmits signals
horizontally over the earth's surface.



** Beeswax for Wood Filler [85]

When filling nail holes in yellow pine use beeswax instead of
putty, as it matches the color well.



** How to Make a Lathe [86]

A small speed-lathe, suitable for turning wood or small metal
articles, may be easily made at very little expense. A lathe of
this kind is shown in the cut (Fig. 1), where A is the headstock,
B the bed and C the tailstock. I run my lathe by power, using an
electric motor and countershaft, but it could be run by foot power
if desired. A large cone pulley would then be required, but this
may be made in the same manner as the small one, which will be
described later.

[Illustration: Assembled Lathe Bed and Bearing Details]

The bed of the machine is made of wood as shown in Figs. 2 and 3,
hardwood being preferable for this purpose. Fig. 2 shows an end
view of the assembled bed, and Fig. 3 shows how the ends are cut
out to receive the side pieces.

The headstock, Fig. 6, is fastened to the bed by means of carriage
bolts, A, which pass through a piece of wood, B, on the under side
of the bed. The shaft is made of 3/4-in. steel tubing about 1/8
in. thick, and runs in babbitt bearings, one of which is shown in
Fig. 5.

To make these bearings, cut a square hole in the wood as shown,
making half of the square in each half of the bearing. Separate
the two halves of the bearing slightly by placing a piece of
cardboard on each side, just touching the shaft. The edges which
touch the shaft should be notched like the teeth of a saw, so as
to allow the babbitt to run into the lower half of the bearing.
The notches for this purpose may be about 1/8 in. pitch and 1/8
in. deep. Place pieces of wood against the ends of the bearing as
shown at A and B, Fig. 4, and drill a hole in the top of the
bearing as shown in Fig. 4.

The bearing is then ready to be poured. Heat the babbitt well, but
not hot enough to burn it, and it is well to have the shaft hot,
too, so that the babbitt will not be chilled when it strikes the
shaft. If the shaft is thoroughly chalked or smoked the babbitt
will not stick to it. After pouring, remove the shaft and split
the bearing with a round, tapered wooden pin. If the bearing has
been properly made, it will split along the line of the notched
cardboard where the section of the metal is smallest. Then drill a
hole in the top as shown at A, Fig. 5, drilling just deep enough
to have the point of the drill appear at the lower side. This
cavity acts as an oil cup and prevents the bearing from running
dry.

The bolts B (Fig. 5) are passed through holes in the wood and
screwed into nuts C, which are let into holes

[Illustration: FIG. 6 Headstock Details]

D, the holes afterward being filled with melted lead.

This type of bearing will be found very satisfactory and may be
used to advantage on other machines. After the bearings are
completed the cone pulley can be placed on the shaft. To make this
pulley cut three circular pieces of wood to the dimensions given
in Fig. 6 and fasten these together with nails and glue. If not
perfectly true, they may be turned up after assembling, by rigging
up a temporary toolrest in front of the headstock.

The tail stock (Fig. 7) is fastened to the bed in the same manner
as the headstock, except that thumb nuts are used on the carriage
bolts, thus allowing the tail stock to be shifted when necessary.
The mechanism of the center holder is obtained by using a 1/2-in.

[Illustration: FIG.7 Details of Tailstock]

pipe, A, and a 1/2-in. lock nut, B, embedded in the wood. I found
that a wooden tool-rest was not satisfactory, so I had to buy one,
but they are inexpensive and much handier than homemade tool rest.
--Contributed by Donald Reeves, Oak Park, Ill.



** To Use Old Battery Zincs [87]

When the lower half of a battery zinc becomes eaten away the
remaining part can be used again by suspending it from a wire as
shown in the cut. Be sure and have a good connection at the zinc
binding post and cover that with melted paraffin. This prevents
corrosion, which would otherwise occur from the action of the sal
ammoniac or other chemical. The wire may be held at the top by
twisting it around a piece

[Illustration: Showing Zinc Suspended]

of wood or by driving a peg through the hole in the porcelain
insulator.
--Contributed by Louis Lauderbach, Newark, N.J.



** Callers' Approach Alarm [87]

This alarm rings so that callers approaching the door may be seen
before they ring the bell and one can exercise his pleasure about
admitting them.

If one has a wooden walk, the alarm is easy to fix up. Take up
about 5 ft. of the walk and nail it together so as to make a
trapdoor that will work easily. Place a small spring under one end
to hold it up about 1/4 in. (A, Fig. 2). Nail a strip of tin along
the under side of the trap near the spring and fasten another
strip on the baseboard, so that they will not touch, save when a
weight is on the trap. Connect up an electric bell, putting the
batteries and bell anywhere desired, and using rubber-covered

[Illustration: Alarm Rings When Caller Approaches]

wire outside the house, and the alarm is complete.

When a person approaching the house steps on the trap, the bell
will ring and those in the house can see who it is before the door
bell rings.
--Contributed by R. S. Jackson, Minneapolis, Minn.



** Easy Method of Electroplating [88]

Before proceeding to electroplate with copper, silver or other
metal, clean the articles thoroughly, as the least spot of grease
or dirt will prevent

[Illustration: Electroplating Apparatus]

the deposit from adhering. Then polish the articles and rub them
over with a cloth and fine pumice powder, to roughen the surface
slightly. Finally, to remove all traces of grease, dip the
articles to be plated in a boiling potash solution made by
dissolving 4 oz. American ash in 1-1/2 pt. of water. Do not touch
the work with the hands again. To avoid touching it, hang the
articles on the wires, by which they are to be suspended in the
plating bath, before dipping them in the potash solution; then
hold them by the wires under running water for ten minutes to
completely remove every trace of the potash.

For plating with copper prepare the following solution: 4 oz.
copper sulphate dissolved in 12 oz. water; add strong ammonia
solution until no more green crystals are precipitated. Then add
more ammonia and stir until the green crystals are re-dissolved
giving an intense blue solution. Add slowly a strong solution of
potassium cyanide until the blue color disappears, leaving a clear
solution; add potassium cyanide again, about one-fourth as much in
bulk as used in the decolorizing process. Then make the solution
up to 2 qt. with water. With an electric pressure of 3.5 to 4
volts, this will give an even deposit of copper on the article
being plated.

A solution for silver plating may be prepared as follows: Dissolve
3/4 oz. of commercial silver nitrate in 8 oz. of water, and slowly
add a strong solution of potassium cyanide until no more white
precipitate is thrown down. Then pour the liquid off and wash the
precipitate carefully. This is best done by filling the bottle
with water, shaking, allowing precipitate to settle and then
pouring off the water. Repeat six times. Having finished washing
the precipitate, slowly add to it a solution of potassium cyanide
until all the precipitate is dissolved. Then add an excess of
potassium cyanide--about as much as was used in dissolving the
precipitate--and make the solution up to 1 qt. with water. This
solution, with an electric pressure of 2 to 4 volts, will give a
good white coat of silver in twenty minutes to half-an-hour; use 2
volts for large articles, and 4 volts for very small ones. If more
solution is required, it is only necessary to double all given
quantities.

Before silver plating, such metals as iron, lead, pewter, zinc,
must be coated with copper in the alkaline copper bath described,
and then treated as copper. On brass, copper, German silver,
nickel and such metals, silver can be plated direct. The deposit
of silver will be dull and must be polished. The best method is to
use a revolving scratch brush; if one does not possess a buffing
machine, a hand scratch brush is good. Take quick, light strokes.
Polish the articles finally with ordinary plate powder.

The sketch shows how to suspend the articles in the plating-bath.
If accumulators are used, which is advised, be sure to connect the
positive (or red) terminal to the piece of silver hanging in the
bath, and the negative (or black) terminal to the article to be
plated. Where Bunsen cells are used, the carbon terminal takes the
place of the positive terminal of the accumulator. --Model
Engineer.



** An Ingenious Electric Lock for a Sliding Door [89]

The apparatus shown in Fig. 1 not only unlocks, but opens the
door, also, by simply pressing the key in the keyhole.

In rigging it to a sliding door, the materials required are: Three
flat pulleys, an old electric bell or buzzer, about 25 ft. of
clothesline rope and some No. 18 wire. The wooden catch, A (Fig.
1), must be about 1 in. thick

[Illustration: Electric Lock for Sliding Door]

and 8 in. long; B should be of the same wood, 10 in. long, with
the pivot 2 in. from the lower end. The wooden block C, which is
held by catch B, Can be made of a 2-in. piece of broomstick. Drill
a hole through the center of this block for the rope to pass
through, and fasten it to the rope with a little tire tape.

When all this is set up, as shown in Fig. 1, make a key and
keyhole. A 1/4 in. bolt or a large nail sharpened to a point, as
at F, Fig. 3, will serve for the key. To provide the keyhole, saw
a piece of wood, I, 1 in. thick by 3 in. square, and bore a hole
to fit the key in the center. Make a somewhat larger block (E,
Fig. 3) of thin wood with a 1/8-in. hole in its center. On one
side of this block tack a piece of tin (K, Fig. 3) directly over
the hole. Screw the two blocks together, being careful to bring
the holes opposite each other. Then, when the point of the key
touches the tin, and the larger part (F, Fig. 3) strikes the bent
wire L, a circuit is completed; the buzzer knocks catch A (Fig.
1), which rises at the opposite end and allows catch B to fly
forward and release the piece of broom-stick C. The weight D then
falls and jerks up the hook-lock M, which unlocks the door, and
the heavier weight N immediately opens it.

Thus, with a switch as in Fig. 3, the door can only be opened by
the person who has the key, for the circuit cannot be closed with
an ordinary nail or wire. B, Fig. 2, shows catch B, Fig. 1,
enlarged; 0, Fig. 2, is the cut through which the rope runs; H,
Fig. 1, is an elastic that snaps the catch back into place, and at
G the wires run outside to the keyhole.

This arrangement is very convenient when one is carrying something
in one hand and can only use the other. Closing the door winds up
the apparatus again.
--Contributed by E. H. Klipstein, 116 Prospect St., East Orange,
New Jersey.



** Parlor Magic for Winter Evenings [90]
By C. H. CLAUDY

You are seated in a parlor at night, with the lights turned low.
In front of you, between the parlor and the room back of it, is an
upright square of brightly burning lights, surrounding a perfectly
black space. The magician stands in front of this, in his shirt
sleeves, and after a few words of introduction proceeds to show
the wonders of his magic cave.

Showing you plainly that both hands are empty, he points with one
finger to the box, where immediately appears a small white china
bowl. Holding his empty hand over this bowl, some oranges and
apples drop from his empty hand into the bowl. He removes the bowl
from the black box, or cave, and hands its contents round to the
audience. Receiving the bowl again, he tosses it into the cave,
but it never reaches the floor--it disappears in midair.

The illusions he shows you are too many to retail at length.
Objects appear and disappear. Heavy metal objects, such as forks,
spoons and jackknives, which have been shown to the audience and
which can have no strings attached to them, fly about in the box
at the will of the operator. One thing changes to another and back
again, and black art reigns supreme.

Now all this "magic" is very simple and requires no more skill to
prepare or execute than any clever boy or girl of fourteen may
possess. It is based on the performance of the famous Hermann, and
relies on a principle of optics for its success. To prepare such a
magic cave, the requisites are a large soap box, a few simple
tools, some black paint, some black cloth, and plenty of candles.

The box must be altered first. One end is removed, and a slit,
one-third of the length from the remaining end, cut in one side.
This slit should be as long as the width of the box and about five
inches wide. On either side of the box, half way from open end to
closed end, should be cut a hole, just large enough to comfortably
admit a hand and arm.

Next, the box should be painted black both inside and out, and
finally lined inside with black cloth. This lining must be done
neatly-no folds must show and no heads of tacks. The interior must
be a dead black. The box is painted black first so that the cloth
used need not be very heavy; but if the cloth be sufficiently
thick, no painting inside is required. The whole inside is to be
cloth-lined, floor, top, sides and end.

[Illustration: Candle stand]

Next, the illumination in front must be arranged. If you can have
a plumber make you a square frame of gas-piping, with tiny holes
all along it for the gas to escape and be lit, and connect this by
means of a rubber tube to the gas in the house, so much the
better; but a plentiful supply of short candles will do just as
well, although a little more trouble. The candles must be close
together and arranged on little brackets around the whole front of
the "cave" (see small cut), and should have little pieces of
bright tin behind them, to throw the light toward the audience.
The whole function of these candles is to dazzle the eyes of the
spectators, heighten the illusion, and prevent them seeing very
far into the black box.

Finally, you must have an assistant, who must be provided with
either black gloves or black bags to go over his hands and arms,
and several black drop curtains, attached to sticks greater in
length than the width of the box, which are let down through the
slit in the top.

The audience room should have only low lights; the room where the
cave is should be dark, and if you can drape portieres between two
rooms around the box (which, of course, is on a table) so much the
better.

The whole secret of the trick lies in the fact that if light be
turned away from anything black, into the eyes of him who looks,
the much fainter light reflected from the black surface will not
affect the observer's eye. Consequently, if, when the exhibitor
puts his hand in the cave, his confederate behind inserts his
hand, covered with a black glove and holding a small bag of black
cloth, in which are oranges and apples, and pours them from the
bag into a dish, the audience sees the oranges and apples appear,
but does not see the black arm and bag against the black
background.

The dish appears by having been placed in position behind a black
curtain, which is snatched swiftly away at the proper moment by
the assistant. Any article thrown into the cave and caught by the
black hand and concealed by a black cloth seems to disappear. Any
object not too large can be made to "levitate" by the same means.
A picture of anyone present may be made to change into a grinning
skeleton by suddenly screening it with a dropped curtain, while
another curtain is swiftly removed from over a pasteboard
skeleton, which can be made to dance either by strings, or by the
black veiled hand holding on to it from behind, and the skeleton
can change to a white cat.

But illusions suggest themselves. There is no end to the effects
which can be had from this simple apparatus, and if the operators
are sufficiently well drilled the result is truly remarkable to
the uninitiated. The illusion, as presented by Hermann, was
identical with this, only he, of course, had a big stage, and
people clothed in black to creep about and do his bidding, while
here the power behind the throne is but a black-veiled hand and
arm. It can be made even more complicated by having two
assistants, one on each side of the box, and this is the reason
why it was advised that two holes be cut. This enables an
absolutely instantaneous change as one uncovers the object at the
moment the second assistant covers and removes the other.

[Illustration: The Magic Cave]

It is important that the assistants remain invisible throughout,
and if portieres are impossible, a screen must be used. But any
boy ingenious enough to follow these simple instructions will not
need to be told that the whole success of the exhibition depends
upon the absolute failure of the audience to understand that there
is more than one concerned in bringing about the curious effects
which are seen. The exhibitor should be a boy who can talk; a good
"patter"--as the magicians call it--is often of more value than a
whole host of mechanical effects and helpers. It is essential that
the exhibitor and his confederate be well drilled, so that the
latter can produce the proper effects at the proper cue from the
former. Finally, never give an exhibition with the "cave" until
you have watched the illusions from the front yourself; so that
you can determine whether everything connected with the draping is
right, or whether some stray bit of light reveals what you wish to
conceal.



** Reversing-Switch for Electrical Experiments [92]

A homemade reversing-switch, suitable for use by students of
electrical and engineering courses in performing experiments, is
shown in the diagram.

[Illustration: FIG.2  Suitable for Students' Use]

Referring to Fig. 1, A represents a pine board 4 in. by 4 in. and
a is a circular piece of wood about 1/4 in. square, with three
brass strips, b1, b2, b3, held down on it by two terminals, or
binding posts, c1, c2, and a common screw, d. Post c1 is connected
to d by means of an insulated wire, making them carry the same
kind of current (+ in the sketch).

About the center piece H moves a disk, held down by another disk F
(Fig. 2), which is fastened through the center piece to the wooden
base, A, by means of two wood screws. On the disk G are two brass
strips, e1 and e2, so arranged that, when handle K is turned to
one side, their one end just slips under the strips b1, b2, or b2,
b3, respectively, making contact with them, as shown in Fig. 2, at
L, while their other ends slide in two half-circular brass plates
f1, f2, held down on disk F by two other terminals, c3, c4, making
contact with them as shown at y, Fig. 2.

The action of the switch is shown in Fig. 1. Connect terminal c1
to the carbon of a battery, and c2 to the zinc. Then, if you turn
handle K to the right, so that the strips e1 and e2 touch b1 and
b2, respectively, terminal c3 will show +, and c1 -- electricity;
vice versa, if you turn the handle to the left so that e1 and e2
touch b2 and b3, respectively, terminal c3 will show - , and c4 +
electricity.

The switch is easy to make and of very neat appearance.



** How to Receive Wireless Telegraph Messages with a Telephone
[92]

Any telephone having carbon in the transmitter (all ordinary
telephones have carbon transmitters) can be used to receive
wireless messages by simply making a few changes in the
connections and providing a suitable antenna. Connect the
transmitter and receiver in series with three dry cells and run
one wire from the transmitter to the antenna. Connect the other
transmitter wire to a water or gas pipe in order to ground it, and
then hold the receiver to your ear. Any wireless telegraph message
within a radius of one mile will cause the transmitter to act as a
coherer, thus making the message audible in the receiver.

By using an ordinary telephone transmitter and receiver and a
1/2-in. jump spark coil, a complete wireless telegraph station may
be made, which will send or receive messages for a radius of one
mile. The accompanying wiring diagram shows how to make the
connections. By putting in an extra switch three of the sending
batteries may be switched in when receiving,

[Illustration: Wiring Diagram for Wireless Telegraph]

thus obviating the necessity of an extra set of batteries.
--Contributed by A. E. Joerin.



** Connecting Up Batteries to Give Any Voltage [93]

Referring to the illustration: A is a five-point switch (may be
homemade) ; B is a one-point switch, and C and C1 are binding
posts. When switch B is closed and A is on No. 1,

[Illustration: Battery Switch]

you have the current of one battery; when A is on No. 2 you
receive the current from two batteries; when on No. 3, from three
batteries; when on No. 4, from four batteries, and when on No. 5,
from five batteries. More batteries may be connected to each point
of switch B.

I have been using the same method for my water rheostat
(homemade). I have the jars of water where the batteries are and
the current coming in at a and b.
--Contributed by Eugene F. Tuttle, Jr., Newark, Ohio.



** A Simple Accelerometer [93]

[Illustration: Accelerometer]

A simple accelerometer for indicating the increase in speed of a
train was described by Mr. A. P. Trotter in a paper read before
the Junior Institution of Engineers of Great Britain. The device
consists of an ordinary 2-ft. rule, A, with a piece of thread tied
to the 22-in. mark, as shown in the sketch, and supporting the
small weight, B, which may be a button or other small object.

The device thus arranged, and placed on the windowsill of the car,
will indicate the acceleration and retardation as follows: Every
1/2 in. traveled by the thread, over the bent portion of the rule,
indicates an increase of or decrease of velocity to the extent of
1 ft. per second for each second. Thus, it the thread moved 2-1/4
in. in a direction opposite to the movement of the train, then the
train would be increasing its speed at the rate of 4-1/2 ft. per
second.

If the thread is tied at the 17-in. mark, then each half inch will
represent the mile per hour increase for each second. Thus if the
thread moves 1 in., it shows that the train is gaining 2 miles an
hour each second.



** An Egg-Shell Funnel [93]

Bottles having small necks are hard to fill without spilling the
liquid. A funnel cannot be used in a small opening, and pouring
with a graduate glass requires a steady hand. When you do not have
a graduate at hand, a half egg-shell with a small hole pricked in
the end will serve better than a funnel. Place the shell in an
oven to brown the surface slightly and it will be less brittle and
last much longer.
--Contributed by Maurice Baudier, New Orleans, La.



** Handy Electric Alarm [94]

An electric alarm which one may turn off from the bed without
arising combined with a light which may be turned on and off from
a lying position, so one can see the time, is the device of H. E.
Redmond, of Burlington, Wis. The alarm clock rests on a shelf, A,

[Illustration: Handy Electric Alarm]

which has a piece of metal, B, fastened in such a position that
the metal rod C, soldered to the alarm winder, will complete the
circuit and ring the bell. The two-point switch D is closed
normally at E, but may be closed at F any time desired, thus
turning on the small incandescent light G, which illuminates the
face of the clock. When the alarm goes off, the bell will continue
to ring until the switch is opened.



** To Keep Dogs and Cats Away from the Garbage-Can [94]

Last summer I was annoyed a great deal by dogs upsetting our
garbage can on the lawn, but finally executed a plan that rid the
yard of them in one afternoon.

I first secured a magneto out of an old telephone, then drove a
spike in a damp place under the porch, attached a wire to the
spike and ran the wire to one of the poles of the magneto. Then I
set the garbage-can on some blocks of wood, being careful not to
have it touch the ground at any point. I next ran a wire from the
other pole of the

[Illustration: Wiring]

magneto to the can, wrapping the wire around the can several
times. Then I sat down on the porch to wait.

It was not long before a big greyhound came along, putting his
forepaws on the top of the can to upset it. At the same instant I
gave the magneto a quick turn, which sent the dog away a very
surprised animal. This was repeated several times during the
afternoon with other dogs, and with the same result. --Contributed
by Gordon T. Lane, Crafton, Pa.



** How to Cross a Stream on a Log [94]

When crossing a water course on a fence rail or small log, do not
face up or down the stream and walk sideways, for a wetting is the
inevitable result. Instead, fix the eye on the opposite shore and
walk steadily forward. Then if a mishap comes, you will fall with
one leg and arm encircling the bridge. --C. C. S.



** Relay Made from Electric Bell [94]

It is not necessary to remove the adjusting-screw when changing an
electric bell into a relay. Simply twist it around as at A and
bend the circuit-breaking contact back as shown. It may be
necessary to remove the head of the screw, A, to prevent
short-circuiting with the armature.
--Contributed by A. L. Macey, New York City.

[Illustration: Relay]



** Foundry Work at Home [95]



** I The Equipment [95]

Many amateur mechanics who require small metal castings in their
work would like to make their own castings. This can easily be
done at home without going to any great expense, and the variety
and usefulness of the articles produced will make the equipment a
good investment.

With the easily made devices about to be described, the young
mechanic can make his own telegraph keys and sounders, battery
zincs, binding posts, engines, cannons, bearings, small machinery
parts, models and miniature objects, ornaments of various kinds,
and duplicates of all these, and many other interesting and useful
articles.

The first thing to make is a molding bench, as shown in Fig. 1. It
is possible to make molds without a bench, but it is a mistake to
try to do this, as the sand is sure to get on the floor, whence it
is soon tracked into the house. The bench will also make the
operation of molding much easier and will prove to be a great
convenience.

The bench should be made of lumber about 1 in. thick and should be
constructed in the form of a trough, as shown. Two cleats, AA,
should be nailed to the front and back to support the
cross-boards, BE, which in turn support the mold while it is being
made. The object of using the cleats and removable cross-boards
instead of a stationary shelf is to give access to the sand, C,
when it is being prepared.

About one or two cubic feet of fine molding-sand will be required,
which may, be purchased at the nearest foundry for a small sum.
Yellow sand will be found a little better for the amateur's work
than the black sand generally used in most foundries, but if no
yellow sand can be obtained the black kind will do. If there is no
foundry

[Illustration: Fig. 1 - Convenient Arrangement of Bench and Tools]

near at hand, try using sand from other sources, giving preference
to the finest sand and that which clings together in a cake when
compressed between the hands. Common lake or river sand is not
suitable for the purpose, as it is too coarse and will not make a
good mold.

For mixing and preparing the sand a small shovel, D, and a sieve,
E, will be required. If desired the sieve may be homemade.
Ordinary wire netting such as is used in screen doors, is about
the right mesh, and this, nailed to replace the bottom of a box,
makes a very good sieve.

The rammer, F, is made of wood, and is wedge-shaped at one end and
flat at the other, as shown. In foundries each molder generally
uses two rammers, but for the small work which will be described
one will be sufficient. An old teaspoon, G, will be found useful
in the molding operations and may be hung on the wall or other
convenient place when not in use.

The cloth bag, H, which can be made of a knitted stocking, is
filled with coal dust; which is used for a parting medium in
making the molds. Take a small lump of soft coal and reduce to
powder by pounding. Screen out all the coarse pieces and put the
remainder in the bag. A slight shake of the bag

[Illustration: Fig. 2; Homemade Flask]

over the mold will then cause a cloud of coal-dust to fall on it,
thus preventing the two layers of sand from sticking, but this
operation will be described more fully later on.

The flask, J, Fig. 1, is shown more clearly in Fig. 2. It is made
of wood and is in two halves, the "cope," or upper half, and the
"drag," or lower part. A good way to make the flask is to take a
box, say 12 in. by 8 in. by 6 in. high, and saw it in half
longitudinally, as shown. If the box is not very strong, the
corners should be braced with triangular wooden strips, A A, which
should be nailed in, previous to sawing. The wooden strips BB are
used to hold the sand, which would otherwise slide out of the
flask when the two halves of the mold are separated.

The dowels, CC, are a very important part of the flask as upon
them depends the matching of the two halves of the mold. A
wedge-shaped piece, CC, is nailed to each end of the cope, and the
lower pieces, DD, are then nailed on the drag so that they just
touch C when the flask is closed. The two halves of the flask will
then occupy exactly the same relative position whenever they are
put together.

After the flask is done make two boards as shown at K, Fig. 1, a
little larger than the outside of the flask. A couple of cleats
nailed to each board will make it easier to pick up the mold when
it is on the floor.

A cast-iron glue-pot makes a very good crucible for melting the
metal, which can be either aluminum, white metal, zinc or any
other metal having a low melting-point. This completes the
equipment with the exception of one or two simple devices which
will now be described.



** II - How to Make a Mold [96]

Having finished making the flask and other equipment, as
described, everything will be ready for the operation of molding.
It would be well for those who have never had any experience in
this line to visit a small brass foundry, where they can watch the
molders at work, as it is much easier to learn by observation; but
they must not expect to make a good mold at the first trial. The
first attempt usually results in the sand dropping out of the cope
when it is being lifted from the drag, either because of
insufficient ramming around the edges or because the sand is too
dry.

A good way to tell when the sand is moist enough is to squeeze it
in the hand. If it forms into a cake and shows all the
finger-marks, it has a sufficient amount of moisture, but if it
crumbles or fails to cake it is too dry. An ordinary watering-pot
will be found useful in moistening the sand, but care should be
taken not to get it too wet, or the hot metal coming in contact
with it when the mold is poured will cause such rapid evaporation
that the mold will "boil" and make a poor casting. A little
practice in this operation will soon enable the molder to
determine the correct amount of moisture.

When molding with sand for the first time it will be necessary to
screen it all before using it, in order to remove the lumps, and
if water is added, the sand should be thoroughly shoveled until
the moisture is evenly distributed. The sand is then ready for
molding.

The operation of making a mold is as follows: The lower half of
the flask, or "drag," and the pattern to be molded are both placed
on the cover board as shown at A. A quantity of sand sufficient to
completely cover the pattern is then sifted into the drag, which
is then filled level with the top with unscreened sand. This is
rammed down slightly with the rammer, and then more sand is added
until

[Illustration: Fig,. 3-Making a Mold]

it becomes heaped up as shown at B. It is then rammed again as
before.

It is impossible to describe just how hard a mold should be
rammed, but by observing the results the beginner can tell when a
mold is too hard or too soft, and thus judge for himself. If the
sand falls out of the flask when lifting the cope, or if it opens
up or spreads after it is poured, it shows that the mold has been
rammed too little, and if the surface of the sand next to the
pattern is cracked it shows that the mold has been rammed too
hard. It will be found that the edges of the mold can stand a
little more ramming than the middle. In finishing the ramming,
pound evenly all over the surface with the blunt end of the
rammer.

After ramming, scrape off the surplus sand with a straight-edged
stick, as shown at C, and scatter about 1/16 in. of loose sand
over the surface for a good bearing. Place another cover board on
top, as shown at D, and by grasping with both hands, as shown,
turn the drag other side up. Remove the upper cover board and
place the upper half of the flask, or "cope," in position, as
shown at E.

In order to prevent the two layers of sand sticking together, the
surface of the sand at E should be covered with coal-dust. This is
done by shaking the coal-dust bag over the flask, after which the
dust on the pattern may be removed by blowing. The cope is then
filled with sand and rammed in exactly the same manner as in the
case of the drag.

After the ramming is done a number of vent holes are made, as
shown at F, from the surface of the mold to the pattern, in order
to allow the escape of air and steam when the mold is being
poured. These vent holes may be made by pushing a wire about the
size of a knitting-needle down through the sand until it touches
the pattern. The "sprue," or pouring-hole, is next cut, by means
of the sprue-cutter shown at the right, which consists of a piece
of thin brass or steel tubing about 3/4 in. in diameter.

Now comes the critical part of the molding operation--that of
lifting the cope from the drag. It is here that the amateur often
becomes discouraged, as the sand is liable to fall out of the cope
and spoil the mold; but with a little practice and patience the
molder can lift the cope every time without breaking it, as shown
at G.

The next operation is that of cutting the gate, which carries the
molten metal from the sprue to the opening left by the pattern.
This is done with a spoon, a channel being cut about 3/4 in. wide
and about 1/4 in. deep. The pattern is then drawn from the mold,
as shown at H, by driving a sharp pointed steel rod into the
pattern and lifting it from the sand. When a metal pattern is used
a thread rod is used, which is screwed into a tapped hole in the
pattern. Before drawing it is well to tap the drawing-rod lightly
with another and larger rod, striking it in all directions and
thus loosening the sand slightly from the pattern. Some molders
tap the pattern gently when withdrawing, as shown at H, in order
to loosen any sand which has a tendency to stick.

After drawing the pattern, place the cope back on the drag, as
shown at J. Place a brick or other flat, heavy object on top of
the mold above the pattern, to prevent the pressure of the melted
metal separating the two halves of the mold, and then pour.



** III- Melting and Pouring [98]

Having prepared one or more molds, the next operation is that of
melting and pouring. An ordinary cast-iron glue-pot makes a good
crucible and can be easily handled by a pair of tongs, made out of
steel rod, as shown in the sketch. In order to hold the tongs
together a small link can be slipped on over the handle, thus
holding the crucible securely.

A second piece of steel rod bent in the form of a hook at the end
is very useful for supporting the weight of the crucible and
prevents spilling the molten metal should the tongs slip off the
crucible. The hook is also useful for removing the crucible from
the fire, which should be done soon after the metal is entirely
melted, in order to prevent overheating. The metal should be
poured into the mold in a small stream, to give the air a chance
to escape, and should not be poured directly into the center of
the opening, as the metal will then strike the bottom hard enough
to loosen the sand, thus making a dirty casting.

[Illustration: Fig. 4 -Pouring the Metal]

If, after being poured, the mold sputters and emits large volumes
of steam, it shows that the sand is too wet, and the castings in
such cases will probably be imperfect and full of holes.

A mold made in the manner previously described may be poured with
any desired metal, but a metal which is easily melted will give
the least trouble. One of the easiest metals to melt and one which
makes very attractive castings is pure tin. Tin melts at a
temperature slightly above the melting point of solder, and,
although somewhat expensive, the permanent brightness and
silver-like appearance of the castings is very desirable. A good
"white metal" may be made by mixing 75% tin, 15% lead, 5% zinc and
5% antimony. The object of adding antimony to an alloy is to
prevent shrinkage when cooling.

A very economical alloy is made by melting up all the old
type-metal, babbitt, battery zincs, white metal and other scrap
available, and adding a little antimony if the metal shrinks too
much in cooling. If a good furnace is available, aluminum can be
melted without any difficulty, although this metal melts at a
higher temperature than any of the metals previously mentioned.

In casting zincs for batteries a separate crucible, used only for
zinc, is very desirable, as the presence of a very small amount of
lead or other impurity will cause the batteries to polarize. A
very good way to make the binding posts is to remove the binding
posts from worn-out dry batteries and place them in the molds in
such a way that the melted zinc will flow around them.

The time required for a casting to solidify varies with the size
and shape of the casting, but unless the pattern is a very large
one about five minutes will be ample time for it to set. The
casting is then dumped out of the mold and the sand brushed off.
The gate can be removed with either a cold chisel or a hacksaw,
and the casting is then ready for finishing.



** Battery Switch [99]

In cases where batteries are used in series and it is desirable to
change the strength and direction of the current frequently, the
following device will be found most convenient. In my own case I
used four batteries, but any reasonable number may be used.
Referring to the figure, it will be seen that by moving the switch
A toward the left the current can be reduced from four batteries
to none, and then by moving the switch B toward the right the
current can be turned on in the opposite

  [Illustration: Battey Switch]

direction to the desired strength. In the various positions of
these two switches the current from each individual cell, or from
any adjacent pair of cells, may be used in either direction.
--Contributed by Harold S. Morton, Minneapolis.



** An Optical Illusion [99]

The engraving shows a perfectly straight boxwood rule laid over a
number of turned brass rings of various sizes. Although the effect
in the illustration

[Illustration: An Optical Illusion]

is less pronounced than it was in reality, it will be noticed that
the rule appears to be bent, but sighting along the rule from one
end will show that it is perfectly straight.

The brass rings also appear distorted. The portions on one side of
the rule do not appear to be a continuation of those on the other,
but that they really are can be proved by sighting in the same
manner as before.
--Contributed by Draughtsman, Chicago.



** New Method of Lifting a Table [99]

To perform this feat effectively the little device illustrated
will be required. To make it take a sheet-iron band, A, 3/4 in.
wide and attach a strap to fasten on the forearm between the wrist
and elbow. Put a sharp needle point, B, through the sheet-iron so
that it extends 3/4 in. outward. Make one of these pieces for each
arm. In lifting the table first show the hands unprepared to the
audience and also a tight table, removing the cover to show that
the surface of the table is not prepared in any way. Then replace
the table,

[Illustration: Table Lifting Device]

rest the hands upon it and at the same time press the needle
points in the arm pieces into the wood of the table, which will be
sufficient to hold it, says a correspondent of the Sphinx. Then
walk down among the audience.



** How to Make a Paddle Boat [100]

A rowboat has several disadvantages. The operation of the oars is
both tiresome and uninteresting, and the oarsman is obliged to
travel, backward.

[Illustration: Paddle Boat]

By replacing the oars with paddles, as shown in the illustration,
the operator can see where he is going and enjoy the exercise much
better than with oars. He can easily steer the boat with his feet,
by means of a pivoted stick in the bottom of the boat, connected
by cords to the rudder.

At the blacksmith shop have a 5/8-in. shaft made, as shown at A,
Fig. 2. It will be necessary to furnish a sketch giving all the
dimensions of the shaft, which should be designed to suit the
dimensions of the boat, taking care that sufficient clearance is
allowed, so that the cranks in revolving will not strike the
operator's knees. If desired, split-wood handles may be placed on
the cranks, to prevent them from rubbing the hands.

The bearings, B, may be made of hardwood, but preferably of iron
pipe filled with melted babbitt. If babbitt is used, either
thoroughly smoke or chalk the shaft or wrap paper around it to
prevent the babbitt sticking. The pieces of pipe may be then
fastened to the boat by means of small pipe straps, such as may be
obtained at any plumber's at a very small cost.

The hubs, C, should be made of wood, drilled to fit the shaft and
mortised out to hold the paddles, D. The covers, E, may be
constructed of thin wood or galvanized iron and should be braced
by triangular boards, as shown in Fig. 1. If galvanized iron is
used, it should be exposed to the weather two or three months
before painting, or the paint will come off, spoiling its
appearance.

[Illustration: Detail of Paddle Boat]



** Peculiar Properties of Ice [100]

Of all the boys who make snowballs probably few know what occurs
during the process. Under ordinary conditions water turns to ice
when the temperature falls to 32 degrees, but when in motion, or
under pressure, much lower temperatures are required to make it a
solid. In the same way, ice which is somewhat below the freezing
point can be made liquid by applying pressure, and will remain
liquid until the pressure is removed, when it will again return to
its original state. Snow, being simply finely divided ice, becomes
liquid in places when compressed by the hands, and when the
pressure is removed the liquid portions solidify and unite all the
particles in one mass. In extremely cold weather it is almost
impossible to make a snowball, because a greater amount of
pressure is then required to make the snow liquid.

This process of melting and freezing under different pressures and
a constant temperature is well illustrated by the experiment shown
in Figs. 1, 2 and 3. A block of ice, A, Fig. 1, is

[Illustration: Experiment with a Block of Ice]

supported at each end by boxes BB, and a weight, W, is hung on a
wire loop which passes around the ice as shown. The pressure of
the wire will then melt the ice and allow the wire to sink down
through the ice as shown in Fig. 2. The wire will continue to cut
its way through the ice until it passes all the way through the
piece, as shown in Fig. 3. This experiment not only illustrates
how ice melts under pressure, but also how it solidifies when the
pressure is removed, for the block will still be left in one piece
after the wire has passed through.

Another peculiar property of ice is its tendency to flow. It may
seem strange that ice should flow like water, but the glaciers of
Switzerland and other countries are literally rivers of ice. The
snow which accumulates on the mountains in vast quantities is
turned to ice as a result of the enormous pressure caused by its
own weight, and flows through the natural channels it has made in
the rock until it reaches the valley below. In flowing through
these channels it frequently passes around bends, and when two
branches come together the bodies of ice unite the same as water
would under the same conditions. The rate of flow is often very
slow; sometimes only one or two feet a day, but, no matter how
slow the motion may be, the large body of ice has to bend in
moving.

This property of ice is hard to illustrate with the substance
itself, but may be clearly shown by sealing-wax, which resembles
ice in this respect. Any attempt to bend a piece of cold
sealing-wax with the hands results in breaking it, but by placing
it between books, as shown on page 65, or supporting it in some
similar way, it will gradually change from the original shape A,
and assume the shape shown at B.



** Return-Call Bell With One Wire [101]

[Illustration: Wiring Diagram]

To use only one wire for a return call bell connect up as shown in
the diagram, using a closed circuit or gravity battery, B. The
current is flowing through both bells all the time, the same as
the coils of a telegraph sounder, but is not strong enough to ring
both connected in series. Pressing either push button, P, makes a
short circuit of that bell and rings the one at the other end of
the line.
--Contributed by Gordon T. Lane, Crafton, Pa.



** Circuit Breaker for Induction Coils [101]

Amateurs building induction coils are generally bothered by the
vibrator contacts blackening, thus giving a high resistance
contact, whenever there is any connection made at all. This
trouble may be done away with by departing from the old
single-contact vibrator and using one with self-cleaning contacts
as shown. An old bell magnet is rewound full of No. 26 double
cotton-covered wire and is mounted

[Illustration: Interrupter for Induction Coil]

upon one end of a piece of thin sheet iron 1 in. by 5 in. as per
sketch. To the other end of the strip of iron is soldered a piece
of brass 1/64 in. by 1/4, in. by 2 in., on each end of which has
been soldered a patch of platinum foil 1/4 in. square.

The whole is connected up and mounted on a baseboard as per
sketch, the contact posts being of 1/4 in. by 1/2 in. brass, bent
into shape and provided with platinum tipped thumb screws. The
advantage of this style of an interrupter is that at each stroke
there is a wiping effect at the heavy current contact which
automatically cleans off any carbon deposit.

In the wiring diagram, A is the circuit breaker; B, the induction
coil, and C, the battery.
--Contributed by A. G. Ward, Wilkinsburg, Pa.



** Spit Turned by Water Power [102]

Many of the Bulgarian peasants do their cooking in the open air
over bonfires. The illustration shows a laborsaving machine in use
which enables the cook to go away and leave meat roasting for an
hour at a time. The

[Illustration: For a Summer Camp]

illustration shows how the spit to which the meat is fastened is
constantly turned by means of a slowly moving water wheel. Some of
our readers may wish to try the scheme when camping out. The
success depends upon a slow current, for a fast-turning wheel will
burn the meat.



** A Short-Distance Wireless Telegraph [102]

The accompanying diagrams show a wireless-telegraph system that I
have used successfully for signaling a distance of 3,000 ft. The
transmitter consists of an induction coil, about the size used for
automobiles, a key or push-button for completing the circuit, and
five dry batteries. The small single-point switch is left open as
shown when sending a message, but when receiving it should be
closed in order that the electric waves from the antenna may pass
through the coherer. The coherer in this case is simply two
electric-light carbons sharpened to a wedge at one end with a
needle

[Illustration: Wiring Diagram for Wireless Telegraph]

connecting the two, as shown. An ordinary telephone receiver is
connected in series with the coherer, as shown. To receive
messages hold the receiver to the ear and close the switch, and
answer by opening the switch and operating the key. --Contributed
by Coulson Glick, Indianapolis.



** Automatic Draft-Opener [102]

A simple apparatus that will open the draft of the furnace at any
hour desired is illustrated. The parts are: A, furnace; B, draft;
C, draft chain; D, pulleys; E, wooden supports; F, vertical lever;
G, horizontal lever; H, cord; I, alarm clock; J, weight. K shows
where and how the draft is regulated during the day, the automatic

[Illustration: Draft Regulator]

device being used to open it early in the morning. The spool on
the alarm clock is fastened to the alarm key by sawing a slit
across the top of the spool and gluing it on. When the alarm goes
off a cord is wound up on the spool and pulls the horizontal lever
up, which releases the vertical lever and allows the weight to
pull the draft open.
--Contributed by Gordon Davis, Kalamazoo, Mich.



** A Window Conservatory [103]

During the winter months, where house plants are kept in the home,
it is always a question how to arrange them so they can get the
necessary light without occupying too much room.

The sketch shows how a neat window conservatory may be made at
small cost that can be fastened on the house just covering a
window, which will provide a fine place for the plants. The frame
(Fig. 2) is made of about 2 by 2-in. material framed together as
shown in Fig. 3. This frame should be made with the three openings
of such a size that a four-paned sash, such as used for a storm
window, will fit nicely in them. If the four vertical pieces that
are shown in Fig. 2 are dressed to the right angle, then it will
be easy to put on the finishing corner boards that hold the sash.

[Illustration: Artistic Window Boxes]

The top, as well as the bottom, is constructed with two small
pieces like the rafters, on which is nailed the sheathing boards
and then the shingles on top and the finishing boards on the
bottom.



** How to Make an Electroscope [103]

An electroscope for detecting electrified bodies may be made out
of a piece of note paper, a cork and a needle. Push the needle
into the cork, and cut the paper in the shape of a small arrow.
Balance the arrow on the needle

[Illustration: Simple Electroscope]

as shown in the sketch, and the instrument will then be complete.
If a piece of paper is then heated over a lamp or stove and rubbed
with a piece of cloth or a small broom, the arrow will turn when
the paper is brought near it.
--Contributed by Wm. W. Grant, Halifax, N. S., Canada.



** Miniature Electric Lighting [104]

Producing electric light by means of small bulbs that give from
one-half to six candle power, and a suitable source of power, is
something that will interest the average American boy.

These circular bulbs range from 1/4 to 2 in. in diameter, and cost
27 cents

[Illustration: FIG. 1]

each complete with base. They are commonly known as miniature
battery bulbs, since a battery is the most popular source of
power. The 1/2-cp. bulbs are usually 2-1/2 volts and take 1/4
ampere of current. It requires about three medium dry cells to
operate it. However, there is now upon the market a battery
consisting of 3 small dry cells connected in series, put up in a
neat case with 2 binding posts, which sells for 25 cents. This is
more economical than dry cells, as it gives about 4 volts and 3
amperes. It will run as large a lamp a 3-1/2 volts, 1 cp., for
some time very satisfactorily. More than one lamp can be run by
connecting the bulbs in parallel, as indicated by Fig. 1, which
shows the special battery with 3 dry cells in the case, and the 2
binding posts for connection with the bulbs. In this case it is
also advisable to connect several batteries in parallel also, so
as to increase the current, but maintain the voltage constant.
Thus the individual cells are in multiple series, i. e., multiples
of series of three. By keeping in mind the ampere output of the
battery and rating of the lamp, one can regulate the batteries as
required. It must be remembered, in this connection, that any
battery which is drawn upon for half of its output will last
approximately three times as long, as if drawn upon for its total
output. Thus, in any system of lamps, it is economical to provide
twice as many batteries as necessary. This also supplies a means
of still maintaining the candle power when the batteries are
partially exhausted, by connecting them in series. However, this
must be done with very great caution, as the lights will be burnt
out if the voltage is too high.

Persons living in the city will find an economical means of
lighting lamps by securing exhausted batteries from any garage,
where they are glad to have them taken away. A certain number of
these, after a rest, can be connected up in series, and will give
the proper voltage.

In conclusion, for battery power: Connecting batteries in series
increases the voltage, and slightly cuts down the current or
amperage, which is the same as that of one battery; while
connecting batteries in parallel increases the amperage, but holds
the voltage the same as that of one cell. Thus, if the voltage and
amperage of any cell be known, by the proper combination of these,
we can secure the required voltage and amperage to light any
miniature lamp. And it might be said that dry cells are the best
for this purpose, especially those of low internal resistance.

[Illustration: FIG.2]

For those having a good water supply there is a more economical
means of maintenance, although the first cost is greater. Fig. 2
shows the scheme. A small dynamo driven by a water motor attached
to a faucet, generates the power for the lights. The cost of the
smallest outfit of the kind is about $3 for the water motor and $4
for the dynamo. This dynamo has an output of 12 watts, and will
produce from 18 to 25 cp., according to the water pressure
obtainable. It is advisable to install the outfit in the basement,
where the water pressure is the greatest, and then lead No. 18 B &
S. double insulated wire wherever needed. The dynamo can also be
used as a motor,

[Illustration: Fig. 3]

and is wound for any voltage up to ten. The winding should
correspond to the voltage of the lamps which you desire to run.
However, if wound for 6 volts, one could run parallel series of
two 3-volt, 1-cp. lamps; making, as in Fig. 3, 11 series, or 22
lights. If wound for 10 volts, it would give 1-1/4 amperes and run
four 6-cp. lamps. Thus, it will be seen that any candle power lamp
can be operated by putting the proper number of lights in each
series, and running the series in parallel. So, to secure light by
this method, we simply turn on the water, and the water
consumption is not so great as might be imagined.

For the party who has electric light in his house there is still
an easier solution for the problem of power. If the lighting
circuit gives 110 volts he can connect eleven 10-volt lamps in
series. These will give 3 cp. each, and the whole set of 11 will
take one ampere of current, and cost about the same as a 32-cp.
lamp, or 1-1/4 cents per hour. Simply connect the miniature
circuit to an Edison plug, and insert in the nearest lamp socket.
Any number of different candle power lamps can be used providing
each lamp takes the same amount of current, and the sum of their
voltages equals the voltage of the circuit used. This arrangement
of small lights is used to produce a widely distributed, and
diffused light in a room, for display of show cases, and for
Christmas trees. Of all these sources of power the two last are
the most economical, and the latter of these two has in its favor
the small initial cost. These lamps are by no means playthings or
experiments, but are as serviceable and practical as the larger
lamps.
--Contributed by Lindsay Eldridge, Chicago.



** How to Make a New Language [105]

Anyone possessing a phonograph can try a very interesting and
amusing experiment without going to any expense. Remove the belt
and replace with a longer one, which can be made of narrow braid
or a number of strands of yarn. The new belt should be long enough
to allow crossing it, thus reversing the machine. This reverses
every sound on the record and changes it to such an extent that
very few words can be recognized.



** How to Make a Cup-and-Saucer Rack [105]

The rack is made of any suitable kind of wood, and the sides, A,
are cut just alike, or from one pattern. The shelves are made in
various widths to fit the sides at the places where they are
wanted. The number of shelves can be varied and to suit the size
of the dishes. Cup hooks are placed on top and bottom shelves. It
is hung on the wall the same as a picture from the molding.
--Contributed by F. B. Emig, Santa Clara, Cal.

[Illustration: Cup-and-Saucer Rack]

Reversing a Small Motor [105]

All that is necessary for reversing the motor is a pole-changing
switch. Connect the two middle posts of the switch with each other
and the two outside posts with each other. Then connect one of the
outside posts of the switch to one brush of the motor and one
middle post to the other brush.

Connect one bar of the switch to one end of the field coil and the
other bar to one pole of the battery, and connect the other pole
of the battery to the other field coil. To reverse the motor,
simply change the switch.

[Illustration: Reverse for a Small Motor]

Referring to the illustration, the letters indicate as follows:
FF, field of motor; BB, brushes of motor; AA, bars of
pole-changing switch; DD, center points of switch; CC, outside
points of switch.
--Contributed by Leonard E. Parker, Plymouth, Ind.



** To Drive Away Dogs [106]

The dogs in my neighborhood used to come around picking up scraps.
After I connected up my induction coil, as shown in the sketch, we
were not bothered with them. A indicates the ground; B, switch;
and C, a bait of meat, or a tempting bone.

[Illustration: Shocking-Machine]

--Contributed by Geo. W. Fry, 903 Vine St., San Jose, Cal.



** An Automatic Lock [106]

The illustration shows an automatic lock operated by electricity,
one cell being sufficient. When the circuit is broken a weight, A,
attached to the end of the armature B, tends to push the other end
of the armature into the screw eye or hook C, which is in the
door, thus locking the door.

To unlock the door, merely push the button E, The magnet then
draws the armature out of the screw eye and the door is unlocked.
The dotted line at D shows the position of the armature when the
circuit is complete and the door unlocked. The weight must be in
proportion to the strength of the magnet. If it is not, the door
will not

[Illustration: Automatic Electric Lock for Doors]

lock, or would remain locked. The button can be hidden, as it is
the key to the lock.
--Contributed by Claude B. Melchior, Hutchinson, Minn.



** Experiment with Two-Foot Rule and Hammer [106]

An example of unstable equilibrium is shown in the accompanying
sketch. All that is needed is a 2-foot rule, a hammer, a piece of
string, and a table or bench. The experiment works best

[Illustration: An Experiment in Equilibrium]

with a hammer having a light handle and a very heavy head.

Tie the ends of the string together, forming a loop, and pass this
around the hammer handle and rule. Then place the apparatus on the
edge of the table, where it will remain suspended as shown.
--Contributed by Geo. P. Schmidt, Culebra, Porto Rico, W. I.



** Simple Current Reverser [107]

On a block of hardwood draw a square (Fig. 1) and drill a hole in
each corner of the square. Fill these holes with mercury and
connect them to four binding posts (Fig. 1).

On another block of wood fasten two wires, as shown in Fig. 2, so
that their ends can be placed in the holes in the first block.
Then connect up with the

[Illustration: Details of Reverser]

motor and battery as in Fig. 3. When the block is placed on with
the big arrow A pointing in the direction indicated in Fig. 3, the
current flows with the small arrows. To reverse turn through an
angle of 90 degrees (Fig. 4). -- Contributed by F. Crawford Curry,
Brockville, Ontario, Canada.



** Alarm Clock to Pull up Furnace Draft [107]

A stout cord, A, is attached to the draft B of the furnace, run
through a pulley, C, in the ceiling and has a window weight, D,
attached at the other end. A small stick is put through a loop in
the cord at about the level of the table top on which the alarm
clock F stands. The other end of stick E is placed under the key G
of the alarm clock. When the alarm rings in the early morning, the
key turns, the stick

[Illustration: Automatic Time Draft-Opener]

falls away, releasing the weight, which pulls the draft open.
--Contributed by Edward Whitney, 18 Gorham St., Madison, Wis.



** How to Transmit Phonograph Music to a Distance [107]

An interesting experiment, and one calculated to mystify anyone
not in the secret, is to transmit the music or speech from a
phonograph to another part of the house or even a greater
distance. For an outdoor summer party the music can be made to
come from a bush, or tree, or from a bed of flowers. The apparatus
is not difficult to construct.

The cut shows the arrangement. Procure a long-distance telephone
transmitter, D, including the mouthpiece, and fasten it to the
reproducer of the phonograph. Also a watch case

[Illustration: The Long-Distance Phonograph]

receiver, R, which fasten to the horn. These parts may be
purchased from any electrical-supply house. Connect two wires to
the transmitter, running one direct to the receiver, and the other
to the battery, thence to a switch, S, and then to the receiver.
The more batteries used the louder will be the sound produced by
the horn, but avoid using too much battery or the receiver is apt
to heat.
--Contributed by Wm. J. Farley, Jr., Camden, N. J.



** How to Make a Telescope [108]

With a telescope like the one here described, made with his own
hands, a farmer boy not many years ago discovered a comet which
had escaped the watchful eyes of many astronomers.

First, get two pieces of plate glass, 6 in. square and 1 in.
thick, and break the corners off to make them round, grinding the
rough edges on a grindstone. Use a barrel to work on, and

[Illustration: Homemade Telescope]

fasten one glass on the top of it in the center by driving three
small nails at the sides to hold it in place. Fasten, with pitch,
a round 4-in. block of wood in the center on one side of the other
glass to serve as a handle.

Use wet grain emery for coarse grinding. Take a pinch and spread
it evenly on the glass which is on the barrel, then take the glass
with the handle and move it back and forth across the lower glass,
while walking around the barrel; also rotate the glass, which is
necessary to make it grind evenly. The upper glass or speculum
always becomes concave, and the under glass or tool convex.

Work with straight strokes 5 or 6 in. in length; after working 5
hours hold the speculum in the sunshine and throw the rays of the
sun onto a paper; where the rays come to a point gives the focal
length. If the glass is not ground enough to bring the rays to a
point within 5 ft., the coarse grinding must be continued, unless
a longer focal length is wanted.

Have ready six large dishes, then take 2 lb. flour emery and mix
in 12 qt. of water; immediately turn the water into a clean dish
and let settle 30 seconds; then turn it into another dish and let
settle 2 minutes, then 8 minutes, 30 minutes and 90 minutes, being
careful not to turn off the coarser emery which has settled. When
dry, turn the emery from the 5 jars into 5 separate bottles, and
label. Then take a little of the coarsest powder, wetting it to
the consistency of cream, and spread on the glass, work as before
(using short straight strokes 1-1/2 or 2 in.) until the holes in
the glass left by the grain emery are ground out; next use the
finer grades until the pits left by each coarser grade are ground
out. When the two last grades are used shorten the strokes to less
than 2 in. When done the glass should be semi-transparent, and is
ready for polishing.

When polishing the speculum, paste a strip of paper 1-1/3 in. wide
around the convex glass or tool, melt 1 lb. of pitch and turn on
to it and press with the wet speculum. Mold the pitch while hot
into squares of 1 in., with 1/4-in. spaces, as in Fig. 1. Then
warm and press again with the speculum, being careful to have all
the squares touch the speculum, or it will not polish evenly. Trim
the paper from the edge with a sharp knife, and paint the squares
separately with jeweler's rouge, wet till soft like paint. Use a
binger to spread it on with. Work the speculum over the tool the
same as when grinding, using straight strokes 2 in. or less.

When the glass is polished enough to reflect some light, it should
be tested with the knife-edge test. In a dark room, set the
speculum against the wall, and a large lamp, L, Fig. 2, twice the
focal length away. Place a large sheet of pasteboard, A, Fig. 2,
with a small needle hole opposite the blaze, by the side of the
lamp, so the light

[Illustration: Detail of Telescope Construction]

from the blaze will shine onto the glass. Place the speculum S,
Fig. 2, so the rays from the needle hole will be thrown to the
left side of the lamp (facing the speculum), with the knife
mounted in a block of wood and edgeways to the lamp, as in K, Fig.
2. The knife should not be more than 6 in. from the lamp. Now move
the knife across the rays from left to right, and look at the
speculum with the eye on the right side of the blade. When the
focus is found, if the speculum is ground and polished evenly it
will darken evenly over the surface as the knife shuts off the
light from the needle hole. If not, the speculum will show some
dark rings, or hills. If the glass seems to have a deep hollow in
the center, shorter strokes should be used in polishing; if a hill
in the center, longer strokes. The polishing and testing done, the
speculum is ready to be silvered. Two glass or earthenware dishes,
large enough to hold the speculum and 2 in. deep, must be
procured. With pitch, cement a strip of board 8 in. long to the
back of the speculum, and lay the speculum face down in one of the
dishes; fill the dish with distilled water, and clean the face of
the speculum with nitric acid, until the water will stick to it in
an unbroken film.

The recipe for silvering the speculum is:

    Solution A:
    Distilled water.............................4 oz.
    Silver nitrate............................100 gr.

    Solution B:
    Distilled water.............................4 oz.
    Caustic stick potash (pure by alcohol)....100 gr.

    Solution C:
    Aqua Ammonia.

    Solution D:
    Sugar loaf................................840 gr.
    Nitric acid................................39 gr.
    Alcohol (Pure).............................25 gr.

Mix solution D and make up to 25 fluid oz. with distilled water,
pour into a bottle and carefully put away in a safe place for
future use, as it works better when old:

Now take solution A and set aside in a small bottle one-tenth of
it, and pour the rest into the empty dish; add the ammonia
solution drop by drop; a dark brown precipitate will form and
subside; stop adding ammonia solution as soon as the bath clears.
Then add solution B, then ammonia until bath is clear. Now add
enough of the solution A, that was set aside, to bring the bath to
a warm saffron color without destroying its transparency. Then add
1 oz. of solution D and stir until bath grows dark. Place the
speculum, face down, in the bath and leave until the silver rises,
then raise the speculum and rinse with distilled water. The small
flat mirror may be silvered the same way. When dry, the silver
film may be polished with a piece of chamois skin, touched with
rouge, the polishing being accomplished by means of a light spiral
stroke.

Fig. 3 shows the position of the glasses in the tube, also how the
rays R from a star are thrown to the eyepiece E in the side of the
tube. Make the tube I of sheet iron, cover with paper and cloth,
then paint to make a non-conductor of heat or cold. Make the
mounting of good seasoned lumber.

Thus an excellent 6-in. telescope can be made at home, with an
outlay of only a few dollars. My telescope is 64 in. long and cost
me just $15, but I used all my spare time in one winter in making
it. I first began studying the heavens through a spyglass, but an
instrument such as I desired would cost $200--more than I could
afford. Then I made the one described, with which I discovered a
new comet not before observed by astronomers.- John E. Mellish.



** How to Make "Freak" Photographs [110]

The "freak" pictures of well-known people which were used by some
daily newspapers recently made everybody wonder how the distorted
photographs were made. A writer in Camera Craft gives the secret,
which proves to be easy of execution. The distortion is
accomplished by the use of prisms, as follows: Secure from an
optician or leaded-glass establishment, two glass prisms, slightly
wider than the lens mount. The flatter they are the less they will
distort. About 20. deg. is a satisfactory angle. Secure them as
shown by the sectional sketch, using strawboard and black paper.
Then make a ring to fit over the lens mount and connect it with
the prisms in such a way as to exclude all light from the camera
except that which passes through the face of the prisms. The inner
surface of this hood must be

[Illustration: Arrangement of Prisms]

dull black. The paper which comes around plates answers nicely. If
the ring which slips over the lens mount is lined with black
velvet, it will exclude all light and hold firmly to the mount,
Place over lens, stop down well after focusing, and proceed as for
any picture.



** Another Electric Lock [110]

The details of the construction of an electrically operated lock
are shown in the illustration. When the door is closed and the
bolt A pushed into position,

[Illustration: Simple Electric Lock]

it automatically locks. To unlock, push the button D, which act
will cause the electromagnet to raise the latch C, when the bolt
may be drawn and the door opened.
--Contributed by A. D. Zimmerman, Boody, Ill.



** How to Mix Plaster of Paris [110]

For the mixing of plaster of Paris for any purpose, add the
plaster gradually to the water, instead of the contrary, says the
Master Painter. Do not stir it, just sprinkle it in until you have
a creamy mass without lumps. Equal parts of plaster and water is
approximately the correct proportion. The addition of a little
vinegar or glue water will retard the setting of the plaster, but
will not preserve its hardening. Marshmallow powder also retards
the setting. In this way the plaster may be handled a long time
without getting hard. If you wish the plaster to set extra hard,
then add a little sulphate of potash, or powdered alum.



** Enlarging with a Hand Camera [111]

Everyone who owns a hand camera has some pictures he would like
enlarged. It is not necessary to have a large camera to do this,
as the process is exceedingly simple to make large pictures from
small negatives with the same hand camera.

A room from which all light may be excluded and a window through
which the light can enter without obstruction from trees or nearby
buildings, with a shelf to hold the camera and a table with an
upright drawing-board attached, complete the arrangement. The back
is taken out of the camera and fitted close against the back of
the shelf, which must be provided with a hole the same size and
shape as the opening in the back of the camera. The negative used
to make the enlarged print is placed in the shelf at A, Fig. 1.
The rays of the clear, unobstructed light strike the mirror, B,
and reflect through the negative, A, through the lens of the
camera and on the board, as shown in Fig. 2. The window must be
darkened all around the shelf.

After placing the negative and focusing the lens for a clear image
on the board, the shutter is set and a bromide paper is placed on
the board. The paper is exposed, developed and fixed by the
directions that are enclosed in the package of bromide papers.

[Illustration: Making Large Pictures with a Small Camera]



** Positioning A Hanging Lamp [111]

Don't pull a lamp hung by flexible cord to one side with a wire
and then fasten to a gas pipe. I have seen a wire become red hot
in this manner. If the lamp hung by a cord must be pulled over,
use a string.

A Curious Compressed Air Phenomenon [111]

Push a pin through an ordinary business card and place the card
against one end of a spool with the pin inside the bore, as shown
in the sketch. Then blow through the spool, and it will be found
that the card will not be blown away, but will remain suspended
without any visible support. This phenomenon is explained by the
fact that the air radiates from the center at a velocity which is
nearly constant, thereby producing a partial vacuum between the
spool and the card. Can the reader devise a practical application
of this contrivance?

[Illustration: Experiment with Spool and Card]



** Simple Switch for Reversing a Current [111]

Take two strips of copper or brass and fasten them together by
means of gutta-percha (Fig. 1); also provide them with a handle.
Saw out a rectangular block about one and one-half times as long
as the brass strips and fasten to it at each end two forked pieces
of copper or brass, as in Fig. 2. Fasten on the switch lever, as
at A and B, Fig. 2, so that it can rotate about these points.
Connect the wires as shown in Fig. 3. To reverse, throw

[Illustration: Simple Current-Reversing Switch]

the lever from one end of the block to the other.
--Contributed by R. L. Thomas, San Marcos, Tex.



** Novel Mousetrap [112]

A piece of an old bicycle tire and a glass fruit jar are the only
materials required for making this trap. Push one end of the tire
into the hole, making sure that there is a space left at the end
so that the mice can get in. Then

[Illustration: A Baitless Trap]

bend the other end down into a fruit jar or other glass jar. Bait
may be placed in the jar if desired, although this is not
necessary.
--Contributed by Geo. Go McVicker, North Bend, Neb.



** Polishing Nickel [112]

A brilliant polish may be given to tarnished nickel by immersing
in alcohol and 2 per cent of sulphuric acid from 5 to 15 seconds.
Take out, wash in running water, rinse in alcohol, and rub dry
with linen cloth.



** Homemade Arc Light [112]

By rewinding an electric-bell magnet with No. 16 wire and
connecting it in series with two electric-light carbons, as shown
in the sketch, a small arc will be formed between the carbon
points when the current is applied. In the sketch, A is the
electric-bell magnet; B, the armature; C C, carbon sockets; D,
carbons, and E E, binding posts. When connected with 10 or 12 dry
batteries this lamp gives a fairly good light.
--Contributed by Morris L. Levy, San Antonio, Tex.

[Illustration: Arc Light]



** Lighting an Incandescent Lamp with an Induction Coil [112]

An incandescent lamp of low candlepower may be illuminated by
connecting to an induction coil in the manner shown in the sketch.
One wire is connected to the metal cap of the lamp and the other
wire is fastened to the glass tip. If the apparatus is then placed
in the dark and the current turned on, a peculiar phosphorescent
glow will fill the whole interior of the lamp. The induction coil
used for this purpose should give a spark about 1/2 in. long or
more.
--Contributed by Joseph B. Bell, Brooklyn.

[Illustration: Geissler Tube]

How to Make a Jump-Spark Coil [113]

The induction coil is probably the most popular piece of apparatus
in the electrical laboratory, and particularly is it popular
because of its use in experimental wireless telegraphy. Ten years
ago wireless telegraphy was a dream of scientists; today it is the
plaything of school-boys and thousands of grown-up boys as well.

Divested of nearly all technical phrases, an induction coil may be
briefly described as a step-up transformer of small capacity. It
comprises a core consisting of a cylindrical bundle of soft-iron
wires cut to proper length. By means of two or more layers of No.
14 or No. 16 magnet wire, wound evenly about this core, the bundle
becomes magnetized when the wire terminals are connected to a
source of electricity.

Should we now slip over this electromagnet a paper tube upon which
has been wound with regularity a great and continuous length of
No. 36 magnet wire, it will be found that the lines of force
emanating from the energized core penetrate the new coil-winding
almost as though it were but a part of the surrounding air itself,
and when the battery current is broken rapidly a second electrical
current is said to be induced into the second coil or secondary.

All or any of the parts of an induction coil may be purchased
ready-made, and the first thing to do is to decide which of the
parts the amateur mechanic can make and which would be better to
buy ready-made. If the builder has had no experience in
coilwinding it would probably pay to purchase the secondary coil
ready-wound, as the operation of winding a mile or more of fine
wire is very difficult and tedious, and the results are often
unsatisfactory. In ordering the secondary it is always necessary
to specify the length of spark desired.

The following method of completing a 1-in. coil illustrates the
general details of the work. The same methods and circuits apply
to small and larger coils. The ready-made secondary is in solid
cylindrical form, about 6 in. long and 2-5/8 in. diameter, with a
hole

[Illustration: Jump-Spark Coil]

through the winding 1-1/4 in. in diameter, as shown in Fig. 1. The
secondary will stand considerable handling without fear of injury,
and need not be set into a case until the primary is completed.
The primary is made of fine annealed No. 24 iron wire cut 7 in. or
8 in. in length, as the maker prefers, and bundled to a diameter
of 7/8 in. The wires may be straightened by rolling two or three
at a time between two pieces of hard wood. If the amateur has
difficulty in procuring this wire, the entire core may be
purchased ready-made.

After the core wires are bundled, the core is wrapped with one or
two layers of manila paper. The straighter the wire the more iron
will enter into the construction of the core, which is desirable.
Beginning half an inch from one end, No. 16 cotton-covered magnet
wire is wound from one end to the other evenly and then returned,
making two layers, and the terminals tied down to the core with
twine. Core and primary are then immersed in boiling paraffine wax
to which a small quantity of resin and beeswax has been added.
This same wax may be used later in sealing the completed coil into
a box. Over this primary is now wrapped one layer of okonite tape,
or same thickness of heavily shellacked muslin. This completed
primary will now allow of slipping into the hole in the secondary.

Should the secondary have been purchased without a case, a wooden
box of mahogany or oak is made, large enough to contain the
secondary and with an inch to spare all around, with room also for
a small condenser; but if it is not convenient to do this work, a
box like that shown in Fig. 2 may be purchased at a small cost. A
7/8-in. hole is bored in the center of one end, through which the
primary core projects 1/8 in. This core is to be used to attract
magnetically the iron head of a vibrating interrupter, which is an
important factor of the coil. This interrupter is shaped as in
Fig. 4, and is fastened to the box in such a way that the vibrator
hammer plays in front of the core and also that soldered
connections may be made inside the box with the screws used in
affixing the vibrator parts to the box. The condenser is made of
four strips of thin paper, 2 yd. long and 5 in. wide, and a
sufficient quantity of tinfoil. When cut and laid in one
continuous length, each piece of tin-foil must overlap the
adjoining piece a half inch, so as to form a continuous electrical
circuit. In shaping the condenser, one piece of the paper is laid
down, then the strip of tin-foil, then two strips of paper and
another layer of foil, and finally the fourth strip of paper. This
makes a condenser which may be folded, beginning at one end and
bending about 6 in. at a time. The condenser is next wrapped
securely with bands of paper or tape, and boiled in pure paraffine
wax for one hour, after which it is pressed under considerable
weight until firm and hard. One of the sheets of tin-foil is to
form one pole of the condenser, and the other sheet, which is
insulated from the first, forms the other pole or terminal. (This
condenser material is purchasable in long strips, ready for
assembling.)

The wiring diagram, Fig. 3, shows how the connections are made.
This method of connecting is suitable for all coils up to 1-1/2
in. spark, but for larger coil better results will be obtained by
using an independent type of interrupter, in which a separate
magnet is used to interrupt the circuit. Besides the magnetic
vibrators there are several other types, such as the mercury
dash-pot and rotary-commutator types, but these will become better
known to the amateur as he proceeds in his work and becomes more
experienced in coil operation.



** Combined Door Bell and Electric Alarm [114]

This device consists of a battery and bell connection to an alarm
clock which also acts as a door bell, the whole being mounted on a
board 18 in. long and 12 in. wide. Referring to the sketch
accompanying this article, the letters indicate as follows: A,
bell; B, battery ; C, switch; D, V-shaped copper strip; E, copper
lever with 1-in. flange turned on one side, whole length, 4 in.;
F, spring to throw lever E down in V-shaped piece to make
connection; G, lever to hold out E when device is used as a door
bell; lines H, go, one from bell, A, and one from battery, B, to
the door; I, shelf for clock.

See that the ring in the alarm key of the clock works easily, so
that when it is square across the clock it will drop down. Fasten
a piece of copper about

[Illustration: Wiring Disgram]

1 in. long to key, then wind the alarm just enough so that the key
stands straight up and down. Place the clock on the shelf and the
key under the flange of lever E. Pull lever G down out of the way
and close the lever on the switch. The alarm key will turn and
drop down, letting lever E drop into the V-shaped piece D and make
connection.

For the door-bell connection close lever on switch C, and put G up
so that D and E do not come in contact. If anyone is ill and you
do not want the bell to ring, open switch C.

The wiring for this device may all be on the back of the board.
The switch and levers are fastened with small screw bolts, which
allows wiring at the back. Saw two spools in half and fasten the
halves to the four corners of the board at the back, and the
apparatus may be put up where one likes.



**v To Build a Small Brass Furnace [115]

Bend a piece of stout sheet iron 23 in. by 12 in. round so that
the inside

[Illustration: Furnace]

diameter is 7 in., and then rivet the seam. Fit in a round piece
of sheet iron for the bottom. Make a hole about the size of a
shilling in the side, 2 in. from the bottom. This is for blowing.

Line the furnace, bottom and sides with fire-clay to a depth of
1/2 in. Use charcoal to burn and an ordinary bellows for blowing,
says the Model Engineer, London. The best blast is obtained by
holding the nozzle of the bellows about an inch from the hole,
instead of close to it.



** Avoid Paper Lamp Shades [115]

Don't wrap paper around a lamp for a shade. You might go away and
forget it and a fire might be started from the heat. Use a glass
or metal shade. That is what they are for.



** Why Gravity Batteries Fail to Work [115]

Many amateur electricians and some professionals have had
considerable trouble with gravity batteries. They

[Illustration: Setting Up a Gravity Battery]

follow directions carefully and then fail to get good results.
The usual trouble is not with the battery itself, but with the
circuit. A gravity battery is suitable only for a circuit which is
normally closed. It is therefore undesirable for electric bells,
induction coils and all other open-circuit apparatus. The circuit
should also have a high resistance. This makes it impractical for
running fan motors, as the motor would have to be wound with fine
wire and it would then require a large number of batteries to give
a sufficiently high voltage.

To set up a gravity battery: Use about 3-1/2 lb. of blue stone, or
enough to cover the copper element 1 in. Pour in water sufficient
to cover the zinc 1/2 in. Short-circuit for three hours, and the
battery is ready for use. If desired for use immediately, do not
short-circuit, but add 5 or 6 oz. of zinc sulphate.

Keep the dividing line between the blue and white liquids about
1/2 in. below the bottom of the zinc. If too low, siphon off some
of the white liquid and add the same amount of water, but do not
agitate or mix the two solutions. This type of battery will give
about 0.9 of a volt, and should be used on a circuit of about 100
milli-amperes.



** A Skidoo-Skidee Trick [116]

In a recent issue or Popular Mechanics an article on "The Turning
Card Puzzle" was described and illustrated. Outside of the
scientific side involved, herein I describe a much better trick.
About the time when the expression "skidoo" first began to be used
I Invented the following trick and

[Illustration: How to Cut the Notches]

called it "Skidoo" and "Skidee," which created much merriment.
Unless the trick is thoroughly understood, for some it will turn
one way, for others the opposite way, while for others it will not
revolve at all. One person whom I now recall became red in the
face by shouting skidoo and skidee at it, but the thing would not
move at all, and he finally from vexation threw the trick into the
fire and a new one had to be made. Very few can make it turn both
ways at will, and therein is the trick.

Take a piece of hardwood 3/8 in. square and about 9 in. long. On
one of the edges cut a series of notches as indicated in Fig. 1.
Then slightly taper the end marked B until it is nicely rounded as
shown in Fig. 2. Next make an arm of a two-arm windmill such as
boys make. Make a hole through the center or this one arm. Enlarge
the hole slightly, enough to allow a common pin to hold the arm to
the end B and not interfere with the revolving arm. Two or three
of these arms may have to be made before one is secured that is of
the exact proportions to catch the vibrations right.

To operate the trick, grip the stick firmly in one hand, and with
the forward and backward motion of the other allow the first
finger to slide along the top edge, the second finger along the
side, and the thumb nail will then vibrate along the notches, thus
making the arm revolve in one direction. To make the arm revolve
in the opposite direction--keep the hand moving all the time, so
the observer will not detect the change which the hand makes
--allow the first finger to slide along the top, as in the other
movement, the thumb and second finger changing places: e. g., In
the first movement you scratch the notches with the thumb nail
while the hand is going from the body, and in the second movement
you scratch the notches with the nail of the second finger when
the hand is coming toward the body, thus producing two different
vibrations. In order to make it work perfectly (?) you must or
course say "skidoo" when you begin the first movement, and then,
no matter how fast the little arm is revolving when changed to the
second movement you must say "skidee" and the arm will immediately
stop and begin revolving in the opposite direction. By using the
magic words the little arm will obey your commands instantly and
your audience will be mystified. If any or your audience presume
to dispute, or think they can do the same let them try it. You
will no doubt be accused of blowing or drawing in your breath, and
many other things in order to make the arm operate. At least it is
amusing. Try it and see.
--Contributed by Charles Clement Bradley Toledo, Ohio.



** Effects of Radium [116]

Radium acts upon the chemical constituents of glass, porcelain and
paper, imparting to them a violet tinge; changes white phosphorus
to yellow, oxygen to ozone, affects photograph plates and produces
many other curious chemical changes.



** Naval Speed Record [116]

On its official trial trip the British torpedo boat destroyer
"Mohawk" attained the record speed of a little over 39 miles an
hour.



** How to Enlarge from Life in the Camera [117]

Usually the amateur photographer gets to a point in his work where
the miscellaneous taking of everything in sight is somewhat
unsatisfying: There are many special fields he may enter, and one
of them is photomicrography. It is usually understood that this
branch of photography means an expensive apparatus. If the worker
is not after too high a magnification, however, there is a very
simple and effective means of making photomicrographs which
requires no additional apparatus that cannot be easily and quickly
constructed at home.

Reproduced with this article is a photograph of dandelion seeds --
a magnification of nine diameters or eighty-one times. The
apparatus which produced this photograph consisted of a camera of
fairly long draw, a means for holding it vertical, a short-focus
lens, and, if possible, but not essential, a means for focusing
that lens in a minute manner. On top of the tripod is the folding
arrangement, which is easily constructed at home with two hinged
boards, an old tripod screw, an old bed plate from a camera for
the screw to fit in, and two sliding brass pieces with sets crews
that may be purchased from any hardware store under the name of
desk sliding braces. To the front board is attached a box,
carrying the lens and the bed of the sliding object carrier, which
can be moved forward and back by the rack and pinion, that also
can be obtained from hardware stores. If the bed for the object
carrier be attached to the bed of the camera instead of to the
front board, the object carrier need have no independent movement
of its own, focusing being done by the front and

[Illustration: Enlargement with a Camera]

back focus of the camera; but this is less satisfactory,
particularly when accurate dimensions are to be determined, says
the Photographic Times. This outfit need not be confined to seeds
alone, but small flowers, earth, chemicals, insects, and the
thousand and one little things of daily life--all make beautiful
subjects for enlarged photographs. These cannot be made by taking
an ordinary photograph and enlarging through a lantern. When a
gelatine dry plate is magnified nine diameters, the grains of
silver in the negative will be magnified also and produce a result
that will not stand

[Illustration: Magnified Nine Diameters]

close examination. Photographs made by photomicrography can be
examined like any other photographs and show no more texture than
will any print.



** Steel Pen Used in Draftsman's Ink Bottle Cork [117]

A steel pen makes an ideal substitute for a quill in the stopper
of the draftsman's ink bottle. The advantage of this substitute is
that there is always one handy to replace a broken or lost pen,
while it is not so with the quill.
--Contributed by George C. Madison, Boston, Mass.



** How to Make a Pilot Balloon [118]
By E. Goddard Jorgensen

Unusual interest is being displayed in ballooning, and as it is
fast becoming the favorite sport many persons would like to know
how to construct a miniature balloon for making experiments. The
following table will give the size, as well as the capacity and
lifting power of pilot balloons:

Diameter.   Cap. in Cu. Ft   Lifting Power.
  5 ft.          65              4 lb.
  6 ft.         113              7 lb.
  7 ft.         179             11 lb.
  8 ft.         268             17 1b.
  9 ft.         381             24 lb.
 10 ft.         523             33 lb.
 11 ft.         697             44 lb.
 12 ft.         905             57 lb.

The material must be cut in suitable shaped gores or segments. In
this article we shall confine ourselves to a 10-ft. balloon. If
the balloon is 10 ft. in diameter, then the circumference will be
approximately 3-1/7 times the diameter, or 31 ft. 5 in. We now
take one-half this length to make the length of the gore, which is
15 ft. 7-1/2 in. Get a piece of paper 15 ft. 7-1/2 in. long and 3
ft. wide from which to cut a pattern, Fig. 1. A line, AB, is drawn
lengthwise and exactly in the middle of the paper, and a line, CD,
is drawn at right angles to AB and in the middle of the paper
lengthways. The intersecting point of AB and CD is used for a
center to ascribe a circle whose diameter is the same as the width
of the paper, or 3 ft. Divide one-quarter of the circle

[Illustration: Pattern for Cutting the Segments]

into 10 equal parts and also divide one-half of the line AB in 10
equal parts. Perpendicular lines are drawn parallel with the line
CD intersecting the division points made on the one-half line AB.
Horizontal and parallel lines with AB are drawn intersecting the
division points made on the one-quarter circle and intersecting
the perpendicular line drawn parallel with CD. A line is now drawn
from B to E and from E to F, and so on, until all the intersecting
lines are touched and the point C is reached. This will form the
proper curve to cut the pattern. The paper is now folded on the
line AB and then on the line CD, keeping the marked part on the
outside. The pattern is now cut, cutting all four quarters at the
same time, on the curved line from B to C. When the paper is
unfolded you will have a pattern as shown in Fig. 2. This pattern
is used to mark the cloth, and after marked is cut the same shape
and size.

The cloth segments are sewed together, using a fine needle and No.
70 thread, making a double seam as shown in Fig. 3. When all seams
are completed you will have a bag the shape shown in Fig. 4. A
small portion of one end or a seam must be left open for
inflating. A small tube made from the cloth and sewed into one end
will make a better place for inflating and to tie up tightly.

It is now necessary to varnish the bag in order to make it retain
the gas. Procure 1 gal. of the very best heavy body, boiled
linseed oil and immerse the bag in it. The surplus oil is squeezed
out by running the bag through an ordinary clothes wringer several
times. The bag is now placed in the sun for a thorough drying. Put
the remaining oil in a kettle with 1/8 lb. of beeswax and boil
well together. This solution is afterward diluted with turpentine
so it will work well. When the bag is dry apply this mixture by
rubbing it on the bag with a piece of flannel. Repeat this
operation four times,

[Illustration: Sewing Segments Together]

being sure of a thorough drying in the sun each time. For indoor
coating and drying use a small amount of plumbic oxide. This will
dry rapidly in the shade and will not make the oil hard.

Fill the bag with air by using a pair of bellows and leave it over
night. This test will show if the bag is airtight. If it is not
tight then the bag needs another rubbing. The next operation is to
fill the bag with gas.

Hydrogen gas is made from iron and sulphuric acid. The amounts
necessary for a 10-ft. balloon are 125 lb. of iron borings and 125
lb. of sulphuric acid. 1 lb. of iron, 1 lb. of sulphuric acid and
4 lb. of water will make 4 cu. ft. of gas in one hour. Secure two
empty barrels of about 52 gal. capacity and connect them, as shown
in Fig. 5, with 3/4-in. pipe. In the barrel, A, place the iron
borings and fill one-half full of clear water. Fill the other
barrel, B, with water 2 in. above the level of the water in barrel
A. This is to give a water pressure head against foaming when the
generator is in action. About 15 lb. of lime should be well mixed
with the water in the barrel B. All

[Illustration: FIG. 5; The Hydrogen Generator]

joints must be sealed with plaster of Paris. Pour in one-half of
the acid into the barrel, A, with the iron borings. The barrels
are kept tight while the generation is going on with the exception
of the outlet, C, to the bag. When the action is stopped in the
generator barrel, A, let the solution run out and fill again as
before with water and acid on the iron borings. The outlet, C,
should be always connected with the bag while the generator is in
action. The 3/4-in. pipe extending down into the cooling tank, B,
should not enter into the water over 8 in. When filled with gas
the balloon is ready for a flight at the will of the operator.



** How to Clean a Clock [119]

It is very simple to clean a clock, which may sound rather absurd.
For an amateur it is not always necessary to take the clock to
pieces. With a little care and patience and using some benzine, a
clean white rag, a sable brush and some oil a clock can be cleaned
and put into first-class running order. The benzine should be
clean and free from oil. You can test benzine by putting a little
on the back of the hand; if it is good it will dry off, leaving
the hand quite clean, but if any grease remains on the hand, it is
not fit to use.

The oil should be of the very best that can be procured. Vegetable
oils should never be used. Clock oil can be procured from your
druggist or jeweler.

All loose dirt should be removed from the works by blowing with
bellows, or a fan, or dusting with a dry brush; in the latter case
great care should be exercised not to injure any of the parts. Dip
the brush in the benzine and clean the spindles and spindle holes,
and the teeth of the escapement wheel. After washing a part, wipe
the brush on the rag and rinse in the benzine; this should be
repeated frequently, until no more dirt is seen.

When the clock has dried, oil the spindle holes carefully; this
may be done with a toothpick or a sliver of woodcut to a fine
point. Oil the tooth of the escapement wheel slightly, using a
fine brush.



** How to Make Blueprint Lantern Slides [120]

Lantern slides of a blue tone that is a pleasing variety from the
usual black may be made from spoiled or old plates which have not
been developed, by fixing, washing well and then dipping five
minutes in the following solution:

    A. Green Iron ammonium citrate    150 gr.
       Water                            1 oz.

    B. Potassium ferrocyanide          50 gr.
       Water                            1 oz.

Prepare the solutions separately and mix equal parts for use, at
the time of employment. Dry the plates in the dark, and keep in
the dark until used. Printing is done in the sun, and a vigorous
negative must be used, says the Moving Picture World. Exposure, 20
to 30 minutes. Wash 10 minutes in running water and dry. Brown or
purple tones may be had by sensitizing with the following solution
instead of the above:

    Distilled water            1 oz.
    Sliver nitrate            50 gr.
    Tartaric or citric acid  1/2 oz.

Bathe the plates 5 minutes, keeping  the fingers out of the
solution, to avoid blackened skin. Dry in the dark. Print to
bronzing under a strong negative; fix in hypo, toning first if
desired.



** A Substitute for a Ray Filter [120]

Not many amateur photographers possess a ray filter. A good
substitute is to use the orange glass from the ruby lamp. This can
be held in position in front of the lens with a rubber band. A
longer exposure will be necessary, but good cloud effects can be
procured in this manner.



** Electric Lamp Experiments [120]

Incandescent electric lamps can be made to glow so that they may
be seen in a dark room by rubbing the globe on clothing or with a
paper, leather or tinfoil and immediately holding near a 1/2-in.
Ruhmkorff coil which is in action but not sparking. The miniature
16 cp., 20 and 22-volt lamps will show quite brilliantly, but the
110-volt globes will not glow. When experimenting with these
globes everything should be dry. A cold, dry atmosphere will give
best results.

*     *     *     *     *     *     *


[Illustration: Annual Regatta, Port Melbourne, Australia]



** How to Make a Simple Wireless Telegraph [121]
By ARTHUR E. JOERIN

An efficient wireless-telegraph receiving apparatus for distances
up to 1,000 ft. may be constructed in the following manner: Attach
a watchcase telephone receiver to a dry cell, or battery, of any
make. The negative pole, or zinc, of the cell is connected to a
ground wire. This is done by attaching to a gas or water pipe. The
positive pole, or carbon, of the cell is connected to the aerial
line. This aerial collector can be made in various ways, either by
using a screen wire or numerous wires

[Illustration: For Distances up to 1000 Feet]

made in an open coil and hung in the air. File a V-shaped groove
in the upper end of the carbon of the cell. Attach a small bent
copper wire in the binding post that is attached to the zinc of
the cell. In the bend of this wire and the V-shaped groove filed
into the carbon, lay a needle. This will complete the receiving
station. Use a spark coil in connection with a telegraph key for
the sending station, making a ground with one wire, and have the
other connected with another aerial line.

By connecting the telephone receiver to the cell and at the same
time having a short circuit a receiving station is made. As the
telephone offers a high resistance, part of the current will try
to take the shorter high resistance through the needle. If the
waves strike across the needle, the resistance is less, and thus
less current travels through the telephone receiver. If the wave
ceases, the resistance between the needle and the carbon is
increased, and as less current will flow the short way, it is
compelled to take the longer metallic way through the windings of
the receiver, which will cause the clickings that can be heard.



** To Preserve Putty [121]

Putty, when left exposed to the air, will soon become dry and
useless. I have kept putty in good condition for more than a year
by placing it in a glass jar and keeping it entirely covered with
water.



** How to Make a Small Storage Battery [121]

The cell of a storage battery consists of two plates, a positive
and a negative, made of lead and placed in a dilute solution of
sulphuric acid. Large batteries made of large cells have a great
number of plates, both positive and negative, of which all
positive plates are connected to one terminal and the negative
plates to the other terminal. The storage cell, as described
below, is the right size to be charged by a few gravity cells and
is easily made.

Secure a piece of 1-3/4-in. lead pipe, 5 in. long, and cut both
ends smooth and square with the pipe. Solder a circular disk of
lead to one end, forming a cup of the pipe. As this cup must hold
the sulphuric acid it must be perfectly liquid-tight. It is also
necessary to get another lead pipe of the same length but only
3/4-in. in diameter. In this pipe should be bored as many 1/8-in.
holes

[Illustration: Battery]

as possible, except for about 1 in. on each end. One end of this
tube is hammered together as shown at A in the sketch to make a
pocket to hold the paste. This, of course, does not need to be
watertight.

A box of wood is made to hold the larger tube or cup. This box can
be square, and the corners left open around the cup can be filled
with sawdust. A support is now made from a block of wood to hold
the tube, B, in place and to keep it from touching the cup C. This
support or block, D, is cut circular with the same diameter as the
lead cup C. The lower portion of the block is cut away so it will
just fit inside of the cup to form a stopper. The center of this
block is now bored to make a hole the same size as the smaller
lead pipe. Place the lead pipe in the hole and immerse it in
smoking hot paraffine wax, and leave it until the wood has become
thoroughly saturated with the hot wax. Use care to keep the wax
from running on the lead at any place other than the end within
the wood block. Two binding-posts should be attached, one to the
positive, or tube B, and the other to the negative, or tube C, by
soldering the joint.

A paste for the positive plate is made from 1 part sulphuric acid
and 1 part water with a sufficient amount of red lead added to
make of thick dry consistency. When mixing the acid and water, be
sure to add the acid to the water and not the water to the acid.
Also remember that sulphuric acid will destroy anything that it
comes in contact with and will make a painful burn if it touches
the hands. Stir the mixture with a stick and when a good dry paste
is formed, put it into the smaller tube and ram it down until the
tube is almost filled. The paste that may have come through the
holes is scraped off and the tube set aside to dry. The large tube
or cup is filled with a diluted solution of sulphuric acid. This
solution should be about one-twelfth acid. The cell is now
complete and ready for storing the current.

The cell may be charged with three gravity cells. These are
connected in series and the positive terminal binding-post on the
storage cell is connected to the wire leading from the copper
plate in the gravity cell. The other plate is connected to the
zinc. The first charge should be run into the cell for about one
week and all subsequent charges should only take from 10 to 12
hours.



** Fitting a Plug in Different Shaped Holes [122]

A certain king offered to give the prince his liberty if he could
whittle a plug that would fit four different shaped holes, namely:
a square hole, a round one, an oblong one and a triangular one,
says the Pathfinder. A broomstick was used to make the plug and it
was whittled in the shape shown

[Illustration: Fits Four Different Shaped Holes]

in Fig. 1. The holes in the different places as shown in Fig. 2,
were fitted by this one plug.



** How to Make a Lightning Arrester [122]

Secure a piece of wood about 3-1/2 in. square that will furnish a
nice finish and round the corners and make a small rounding edge
as shown in the sketch. From a piece of brass 1/16 in. thick cut
two pieces alike, A and B, and match them together, leaving about
1/16 in. between their upper edges and fasten them to the wood
with binding-posts. The third piece of brass, C, is fitted

[Illustration: Lightning Arrester]

between the pieces A and B allowing a space of 1/16-in. all around
the edge. One binding-post and a small screw will hold the piece
of brass, C, in place on the wood. The connections are made from
the line wires to the two upper binding-posts and parallel from
the lower binding-posts to the instrument. The third binding-post
on C is connected to the ground wire. Any heavy charge from
lightning will jump the saw teeth part of the brass and is
grounded without doing harm to the instruments used. --Contributed
by Edwin Walker, Chicago, Ill.



** A Home-Made Punt [123]

A flat bottom boat is easy to make and is one of the safest boats,
as it is not readily overturned. It has the advantage of being
rowed from either end, and has plenty of good seating capacity.

This punt, as shown in Fig. 1, is built 15 ft. long, about 20 in.
deep and 4 ft. wide. The ends are cut sloping for about 20 in.
back and under. The sides are each made up from boards held
together with battens on the inside of the boat near the ends and
in the middle. One wide board should be used for the bottom piece.
Two pins are driven in the top board of each side to serve as
oarlocks.

The bottom is covered with matched boards not over 5 in. wide.
These pieces are placed together as closely as possible, using
white lead between the joints and nailing them to the edges of the
side boards and to a keel strip that runs the length of the punt,
as shown in Fig. 2. Before nailing the boards place lamp wicking
between them and the edges of the side boards. Only galvanized
nails should be used. In order to make the punt perfectly
watertight it is best to use the driest lumber obtainable. At one
end of the punt a skag and a rudder can be attached as shown in
Fig. 3.

[Illustration: Easy to Build and Safe to Use]



** Photographers' Printing Frame Stand [123]

When using developing papers it is always bothersome to build up
books or

[Illustration: Adjustable to Any Height]

small boxes to make a place to set the printing frame in front of
the light. Details for making a small stand that is adjustable to
any desired height are shown in the sketch. In Fig. 1 is shown the
construction of the sliding holder. A piece of 1/4-in. gas pipe,
A, is cut 1 in. long and fitted with a thumbscrew, B. The piece of
pipe is soldered to the middle on the back side of a piece of
metal that is about 4 by 4-1/2 in. with its lower edge turned up
to form a small shelf as shown at C. The main part of the stand is
made by inserting a 5/16-in. rod tightly into a block of hard
maple wood that is 1 in. thick and 3-1/2 in. square (Fig 2). The
pipe that is soldered to the metal support will slide up and down
the rod and the thumbscrew can be set to hold it at the desired
point.



** Heat and Expansion [124]

Take an electric light bulb from which the air has not been
exhausted and immerse it in water and then break off the point. As
there is a vacuum in the bulb it will quickly fill with water.
Shake the bulb gently until a part of the water is out and then
screw the bulb into a socket with the point always downward. Apply
the current and the heated air inside will soon expand and force
the water out with great rapidity. Sometimes this experiment can
be done several times by using the same bulb.
--Contributed by Curtiss Hill, Tacoma, Wash.



** Photographing a Streak of Lightning [124]

The accompanying illustration is a remarkable photograph of a
streak of lightning. Many interesting pictures of this kind can be
made during a storm at night. The camera is set in a place where
it will not get wet and left standing with the shutter open and
the plate ready for the exposure. Should a lightning streak appear
within the range of the lens it will be made on the plate, which
can be developed in the usual manner. It will require some
attention to that part of the sky within the range of the lens so
as to not make a double exposure by letting a second flash enter
the open lens.
--Contributed by Charles H. Wagner.

*     *     *     *     *

Borax may be used as a solvent for shellac gum.

*     *     *     *     *



** How to Make a Small Single-Phase Induction Motor [124]
By C. H. Bell

The following notes on a small single-phase induction motor,
without auxiliary phase, which the writer has made, may be of
interest to some of our readers, says the Model Engineer. The
problem to be solved was the construction of a motor large enough
to drive a sewing machine or very light lathe, to be supplied with
110-volt alternating current from a lighting circuit, and to
consume, if possible, no more current than a 16-cp. lamp. In
designing, it had to be borne in mind that, with the exception of
insulated wire, no special materials could be obtained.

[Illustration: Motor]

The principle of an induction motor is quite different from that
of the commutator motor. The winding of the armature, or "rotor,"
has no connection with the outside circuit, but the current is
induced in it by the action of the alternating current supplied to
the winding of the field-magnet, or "stator." Neither commutator
nor slip rings are required, and all sparking is avoided.
Unfortunately, this little machine is not self-starting, but a
slight pull on the belt just as the current is turned on is all
that is needed, and the motor rapidly gathers speed provided no
load is put on until it is in step with the alternations of the
supply. It then runs at constant speed whether given much or
little current, but stops if overloaded for more than a few
seconds.

The stator has four poles and is built up of pieces of sheet iron
used for stove pipes, which runs about 35 sheets to the inch. All
the pieces are alike and cut on the lines with the dimensions as
shown in Fig. 1, with the dotted line, C, to be filed out after
they are placed together. Each layer of four is placed with the
pointed ends of the pieces alternately to the right and left so as
to break joints as shown in Fig. 2. The laminations were carefully
built up on a board into which heavy wires had been driven to keep
them in place until all were in position and the whole could be
clamped down. In the middle of the pieces 1/4-in. holes, B, were
then drilled and 1/4-in. bolts put in and tightened up, large
holes being cut through the wood to enable this to be done. The
armature tunnel was then carefully filed out and all taken apart
again so that the rough edges could be scraped off and the
laminations given a thin coat of shellac varnish on one side.
After assembling a second time, the bolts were coated with shellac
and put into place for good. Holes 5-32 in. in diameter were
drilled in the corners, A, and filled with rivets, also varnished
before they were put in. When put together they should make a
piece 2 in. thick.

This peculiar construction was adopted because proper stampings
were not available, and as every bit of sheet iron had to be cut
with a small pair of tinners' snips, it was important to have a
very simple outline for the pieces. They are not particularly
accurate as it is, and when some of them got out of their proper
order while being varnished, an awkward job occurred in the magnet
which was never entirely corrected. No doubt some energy is lost
through the large number of joints, all representing breaks in the
magnetic circuit, but as the laminations are tightly held together
and the circuit is about as compact as it could possibly be,
probably the loss is not as great as it would appear at first
sight.

The rotor is made of laminations cut from sheet iron, as shown in
Fig. 3, which were varnished lightly on one side and clamped on
the shaft between two nuts in the usual way. A very slight cut was
taken in the lathe afterwards to true the circumference. The shaft
was turned from 1/2-in. wrought iron, no steel being obtainable,
and is shown with dimensions in Fig. 4. The bearings were cast of
babbitt metal, as shown in Fig. 5, in a wooden mold and bored to
size with a twist drill in the lathe. They are fitted with
ordinary wick lubricators. Figures 6 and 7 are sections showing
the general arrangement of the machine.

The stator is wound full with No. 22 double cotton-covered copper
wire,

[Illustration: Motor]

about 2-1/2 lb. being used, and the connections are such as to
produce alternate poles--that is, the end of the first coil is
joined to the end of the second the beginning of the second to the
beginning of the third, and the end of the third to the end of the
fourth, while the beginnings of the first and fourth coils connect
to the supply.

The rotor is wound with No. 24 double cotton-covered copper wire,
each limb being filled with about 200 turns, and all wound in the
same direction. The four commencing ends are connected together on
one side of the rotor and the four finishing ends are soldered
together on the other. All winding spaces are carefully covered
with two layers of cambric soaked in shellac, and as each layer of
wire was wound, it was well saturated with varnish before the next
was put on.

This type of motor has drawbacks, as before stated, but if regular
stampings are used for the laminations, it would be very simple to
build, having no commutator or brushes, and would not easily get
out of order. No starting resistance is needed, and as the motor
runs at constant speed, depending upon the number of alternations
of the supply, a regulating resistance is not needed.



** Carbolic Acid Burns [126]

The pain of carbolic acid burns can be relieved promptly by
washing with alcohol, if applied immediately. If too late for
alcohol to be of use, brush with water containing saturated
solution of picric acid.



** How to Make a Paper Book Cover [126]

Book covers become soiled in handling and especially school books.
Various methods are applied for making a temporary cover that will
protect the book cover. A paper cover can be quickly made by using
a piece of paper larger than both covers on the book when they are
open. Fold the paper on the long dotted line, as shown in Fig. 1.
When the folds are made the paper should then be just as wide as
the book cover is high. The ends are then folded on the short
dotted lines, which will make it appear as shown in Fig. 2. The
paper thus folded is placed on the book cover as shown in Fig. 3.
--Contributed by C. E. McKinney, Jr., Newark, N. J.

[Illustration: To Protect Book Covers]



** How to Make Lantern Slides [127]

The popularity of lantern slides, and especially of colored ones,
as a means of illustrating songs, has caused so large a demand for
this class of work that almost any amateur may take up slide
making at a good profit. The lantern slide is a glass plate,
coated with slow and extremely fine-grained emulsion. The size is
3-1/4 by 4 in. A lantern slide is merely a print on a glass plate
instead of on paper. Lantern slides can be made in two different
ways. One is by contact, exactly the same as a print is made on
paper, and the other by reduction in the camera. In making slides
by contact, select the negative and place it in the printing frame
and put the lantern plate upon it, film to film. Clamp down the
back and expose just as in making a print. A good method of
exposing is to hold a lighted match about 3 in. from the frame for
three or more seconds according to the density.

Development is carried on in the same manner as with a negative.
The image should appear in. about a minute, and development should
be over in three or four minutes. If the exposure has been
correct, the high lights will stay white throughout the
development and will come out as clear glass after fixing. It is
best to use the developers recommended by the manufacturer of the
plates used, the formulas being found in each package of plates.
It is best, also, to use a plain fixing bath, which must be fresh
and kept as cool as possible in hot weather.

The lantern-slide film that is new on the market can be handled in
the same manner as the glass-plate slide, except that the binding
is different. The results are the same and the slides are not so
bulky to handle. Being unbreakable, they are much used by
travelers. The manner of binding them for use in a lantern is
described on the circular enclosed with the film.

[Illustration: The Camera as It is Arranged in Front of the Window
for Reducing the Size of a Picture, and the Method of Binding the
Slides]

When the negative is larger than the lantern-slide plate, and it
is desirable to reduce the entire view upon the slide, a little
extra work will be necessary. Select a room with one window, if
possible, and fit a light-proof frame into it to keep out all
light with the exception of a hole in which to place the negative,
as shown in Fig. 1. Unless this hole is on a line with the sky it
will be necessary to place a sheet of white cardboard at an angle
of 45 deg. on the outside of the frame to reflect the light
through the negative as shown in Fig. 2. Make or secure an inside
kit to place in the plate holder of your camera to hold the
lantern slide plate as shown in Fig. 3. Draw lines with a pencil,
outlining on the ground glass of the camera the size of the
lantern slide plate, and in the place where the plate will be in
the plate holder when placed in position in the camera. This will
enable you to focus to the proper size. Place the camera in front
of the hole in the frame, place the negative in the hole and focus
the camera for the lantern slide size. Expose with a medium stop
for about 20 seconds and treat the plate the same as with the
contact exposure.

When dry the lantern slide plate may be tinted any color by means
of liquid colors. These can be purchased from any photo material
store. In coloring the slide plate it is only necessary to moisten
the gelatine film from time to time with a piece of cloth dampened
in water. The colors may then be spread evenly with a soft brush,
which should be kept in motion to prevent spots.

The slide is put together by placing a mat made of black paper, as
shown in Fig. 4, on the gelatine side of the lantern slide, A,
Fig. 5, and then a plain glass, B, over the mat, C, and the three
bound together with passepartout tape, D. Contrasty negatives make
the best slides, but the lantern slide plate should be made
without any attempt to gain density.



** HOW TO MAKE A PORCH SWING CHAIR [128]

The material needed for making this porch swing chair are two
pieces of round wood 2-1/2 in. in diameter and 20 in. long, and
two pieces 1-1/4 in. in diameter and 40 in. long. These longer
pieces can be made square, but for appearance it is best to have
them round or square with the corners rounded. A piece of canvas,
or other stout cloth, 16 in. wide and 50 in. long, is to be used
for the seat. The two short pieces of wood are used for the ends
of the chair and two 1-in. holes are bored in each end of them
1-1/2 in. from the ends, and between the holes and the ends
grooves are cut around them to make a place to fasten ropes, as
shown at B, Fig. 1. The two longer pieces are used for the sides
and a tenon is cut on each end of them to fit in the 1-in. holes
bored in the end pieces, as shown at A, Fig. 1. The canvas is now
tacked on the end pieces and the pieces given one turn before
placing the mortising together.

[Illustration: Swing Chair]

The chair is now hung up to the porch ceiling with ropes attached
to a large screw eye or hook. The end of the chair to be used for
the lower part is held about 16 in. from the floor with ropes
direct from the grooves in the end pieces to the hook. The upper
end is supported by using a rope in the form of a loop or bail, as
shown in Fig. 2. The middle of the loop or bail should be about 15
in. from the end piece of the chair. Another rope is attached to
the loop and through the hook and to a slide as shown. This will
allow for adjustment to make the device into a chair or a hammock.
--Contributed by Earl R. Hastings, Corinth, Vt.



** How to Find the Blind Spot in the Eye [129]

Make a small black circular dot 1/2 in. in diameter on a piece of
cardboard and about 3 in. from the center of this dot draw a star.
Hold the cardboard so that the star will be directly in front of
one eye, while the dot will be in front of the other. If the star
is in front of the left eye, close the right eye and look steadily
at the star while you move the cardboard until the point is
reached where the dot disappears. This will prove the presence of
a blind spot in a person's eye. The other eye can be given the
same experiment by turning the cardboard end for end. The blind
spot does not indicate diseased eyes, but it simply marks the
point where the optic nerve enters the eyeball, which point is not
provided with the necessary visual end organs of the sight, known
as rods and cones.



** Beeswax Substitute [129]

A wax from the rafie palm of Madagascar is being used as a
substitute for beeswax.



** Home-Made Water Wheel Does Family Washing [129]

[Illustration: Water Wheel]

The accompanying sketch illustrates a very ingenious device which
does the family washing, as well as to operate other household
machines. A disk 1 in. in thickness and 10 in. in diameter was cut
from a piece of rough board, and on its circumference were nailed
a number of cup-shaped pieces cut from old tin cans. A hole was
then bored through the center of the disk and an old piece of iron
rod was driven through to form a shaft. Two holes were then bored
opposite each other through the sides of a wooden box in which the
disk was placed, allowing the shaft to project through the holes.
A small grooved wooden pulley was driven tightly on one of the
projecting ends of the shaft. The top of the box was then tightly
closed and a hole, large enough to admit the nozzle of a garden
hose, was bored so that the jet of water would flow upon the tin
buckets that were nailed to the circumference of the wheel or
disk. Another hole was bored in the bottom of the box large enough
to allow the waste water to run away freely. A belt, made from an
ordinary sash cord, was run from the small pulley on the
waterwheel to a large pulley, as shown in Fig. 1. A pitman was
attached to the large pulley, which operates the washing machine
by its reciprocating motion, and the length of the stroke is
adjusted by moving the position of the hinge joint on the arm of
the washing machine, as shown in Fig. 2. The pressure at the
nozzle is about 20 lb. per square inch, and is sufficient to drive
the waterwheel under all ordinary circumstances.
--Contributed by P. J. O'Gara, Auburn, Cal,



** An Optical Illusion [130]

When looking at the accompanying sketch you will say that the
letters are alternately inclined to the right and left. They are
not so and can be proved by measuring the distance of the top and
bottom of any vertical strokes from the edge of the entire block.
They will be found to be exactly the same distance. Or take any of
the horizontal strokes of the four letters and see how far their
extremities are from the top and bottom of the entire block. It
will be found that a line joining the extremities of the strokes
are strictly parallel to the top or bottom and that they are not
on a slant at all. It is the slant of the numerous short lines
that go to make up the letter as a whole that deceives the eye.

[Illustration: Illusion]



** Home-Made Micrometer [130]

It often becomes necessary to find the thickness of material so
thin, or inconvenient to measure, that a rule or other measuring
device will not serve the purpose. A simple, fairly accurate, and
easily made apparatus of the micrometer form may be constructed as
shown by the accompanying sketch. Secure a common iron or brass
bolt about 1/4-in. in diameter and about 2-1/2 in. long, with as
fine a thread as possible, and the thread cut to within a short
distance of the head of the bolt. The head of the bolts should
have a slot cut for the use of a screwdriver. Clamp together two
blocks of wood with square corners which are about 1 in. wide, 3/4
in. thick and 2-1/2 in. long and fasten them together with small
pieces nailed across the ends. The width of the blocks will then
be about 2 in. Bore a 1/4-in. hole through the center of the
blocks in the 2 in. direction. Remove the clamp and set the nut
into one of the blocks, so that the hole will be continuous with
the hole in the wood. Cut out a piece from the block combination,
leaving it shaped like a bench, and glue the bottoms of the legs
to a piece of thin board about 2-1/2 in. square for a support.

Solder one end of a stiff wire that is about 2 in. long to the
head of the bolt at right angles to the shaft, and fix a disc of
heavy pasteboard with a radius equal to the length of the wire,
and with its circumference graduated into equal spaces, to serve
in measuring revolutions of the end of the wire, to the top of the
bench. Put the bolt in the hole, screwing it through the nut,

[Illustration: Micrometer]

and the construction is complete. The base is improved for the
measuring work by fastening a small piece of wood on the board
between the legs of the bench. A small piece of metal is glued on
this piece of wood at the point where the bolt meets it.

Find the number of threads of the screw to the inch by placing the
bolt on a measuring rule, and counting the threads in an inch of
its length. The bolt in making one revolution will descend a
distance equal to the distance between the threads.

The device is used by placing the object whose thickness is to be
measured on the base under the bolt, and screwing the bolt down
until its end just touches the object, then removing the object,
and screwing the bolt down until its end just touches the base,
carefully noting while doing so the distance that the end of the
wire moves over the scale. The part of a rotation of the bolt, or
the number of rotations with any additional parts of a rotation
added, divided by the number of threads to the inch, will be the
thickness of the object. Quite accurate measurements may be made
with this instrument, says the Scientific American, and in the
absence of the expensive micrometer, it serves a very useful
purpose.



** Another Electric Lamp Experiment [131]

Break a portion of the end off from a 16-cp. globe that has been
thrown away as useless. Shake the globe until all the filament is
broken away, leaving only the ends of the platinum wire exposed.
Screw the globe into a socket that sets upright and fill it with
salt water. Make one connection to the socket from the positive
wire of a 110 volt circuit and the other to a ground. When the
current is turned on small stars will be seen in the globe, which
show up fine at night.
--Contributed by Lindsay McMillan, Santa Maria, Oal.



** Removing Ink Stains [131]

Two or three applications of milk which are wiped up with a dry
cloth will remove india ink spots on carpets.



** Feat of Balancing on Chairs [131]

[Illustration: For Boys Balanacing]

Among the numerous physical exercises is the feat of balancing on
the two rear legs of a chair while one foot rests on the front
part of the seat and the other on the back of the chair. This may
appear to be a hard thing to do, yet with a little practice it may
be accomplished. This exercise is one of many practiced by the
boys of a boys' home for an annual display given by them. A dozen
of the boys will mount chairs at the same time and keep them in
balance at the word of a commanding officer.



** How to Make a Merry-Go-Round Swing [131]

A 6 by 6-in. piece of wood 12 ft. long is used for the center
pole. Bore a 3/4-in. hole in each end to a depth of 6 in. Place a
3/4-in. bolt in each hole, the bolt being long enough to protrude
2 in. beyond the end of the wood. Short pieces of wood are nailed
on the center pole about 2 ft. from the end that is to be used for
the bottom. This should form a hub on which to place the inner
ends of the extending spokes that hold the platform. The spokes
are made from twelve pieces of 2 by 4-in. material 12 ft. long.

Usually a wheel can be found in a scrap pile suitable to place on
the pin that is in the top end of the center pole. The wheel
should be open

[Illustration: Side and Top View]

or have spokes. This wheel is used to attach wires for guying. The
bottom pin in the center pole is placed in a hole that is bored
into a block of wood about 12-in. square and 3 or 4 in. thick. A
piece of sheet metal should be drilled and placed on the pin
between the block and end of the pole to make a smooth bearing.
The center pole is now placed in position and guyed with six wires
that are about 35 ft. long. Stakes are driven into the ground and
the wires fastened to them and to the wheel at the top end of the
pole. Care should be taken when attaching the wires to get the
center pole to stand perpendicular. Twelve hooks should be placed
at equal distances around the center pole about 1 ft. from the top
end. Wires are fastened to these hooks and to the twelve 2 by
4-in. pieces used for the spokes. The wires should be tied around
each spoke about 2 ft. from the ends. Space the spokes with equal
divisions and cover the outer 2 ft. of the ends with boards, as
shown in the plan sketch on the right hand end of the drawing. The
boards may be nailed or bolted. If bolted and the wires made in a
loop at the hooks, the swing can easily be taken apart and changed
from one place to another.
--Contributed by A. O. Graham, Fort Worth, Tex.



** Home-Made Arc Lamp [132]

The frame of the lamp is made from bar metal 3/4 in. wide and 1/8
in. thick, bent and welded to make a continuous loop in the shape
as shown at G in the sketch. This frame should be about 10-1/2 in.
long with the upper or wider part 4 in. long, and the lower part
6-1/2 in. long. The width should be about 5-1/4 in. at

[Illustration: Arc Lamp]

the top and 4 in. at the bottom. A cross bar, L, made of the same
material, is fitted into the off-set in the frame and riveted.
Holes are drilled through the frame and brass bushings, H and J,
are fitted for bearings to receive the adjusting brass rod, B,
which should be 1/4 in. in diameter. A brass curtain rod can be
used for the rod B, and on its lower end a socket, P, is soldered.

A piece of brass 2 in. long, 1/2 in. wide and 1/8 in. thick is
used for the armature, A, to be operated by the magnet coil, C.
The coil, C, is made in the usual manner by wrapping No. 14
cotton-covered magnet wire on a wooden spool that has a soft iron
core. The spool is about 2-1/2 in. long. The armature, A, is
drilled, making a hole just a little larger than the rod, B, and
is adjusted in place by two set screws, D and E. A soft piece of
iron, F, is fastened to the opposite end of the armature with a
screw, which should be placed directly under the end of the coil's
core. This end of the armature may be kept from swinging around by
placing it between a U-shaped piece of brass fastened to the cross
piece L. At the bottom end of the frame, and directly centering
the holes H and J, a hole is drilled to receive a hard rubber
bushing, R, for insulating the brass ferrule, S, that holds the
lower carbon.

One connection is made from the main to the upper binding-post,
which is in turn connected to one terminal of the coil, C, the
other coil terminal being attached to the frame. The other main
connection is made to the lower binding-post, which is also
connected to the brass ferrule, S, by soldering. The two
binding-posts are insulated from the frame the same as the ferrule
S. When using on a 110-volt circuit there must be some resistance
in connection, which may be had by using German silver wire, or a
water rheostat heretofore described.
--Contributed by Arthur D. Bradlev. Randolph, Mass.



** Irrigation [132]

The Mexican government has appropriated $25,000,000 for irrigation
work.



** How to Hang Your Hat on a Lead Pencil [133]

Take a smooth hexagon lead pencil, one without either rubber or
metal end, and place it against a door or window casing; then with
a firm, heavy pressure slide the pencil some 3 or 4 in. and it
will stay as if glued to the casing. You may now hang your hat on
the end of the pencil.

When you slide the pencil along the casing, do it without any
apparent effort, and it will appear to your audience as though you
had hypnotized it. This is a very neat trick if performed right.
Figure 1 shows the pencil on the casing and Fig. 2 the hat hanging
on it.

[Illustration: Pencil Trick]



** Tying a Knot for Footballs [133]

One of the most prominent English football clubs kept the tying of
this knot on the rubber hose of their football a secret and never
allowed all of its members to know how it was tied. This tie can
be used on grain sacks, and in numerous other like instances. Make
one loop in the cord and then another exactly the same way, as

[Illustration: A Secure Knot]

shown in Fig. 1, placing the end of the cord under the first loop,
then pulling at each end of the cord as in Fig. 2.--A.E.J.



** Stove polish [133]

Stove polish consists of 2 parts graphite, 4 parts copperas and 2
parts bone black, mixed with water to form a paste.



** How to Give an Electric Shock While Shaking Hands [133]

There is nothing quite so startling as to receive an electric
shock unexpectedly and such a shock may be given to a friend while
shaking hands upon meeting. The shock produced is not harmful and
the apparatus can be carried in the pocket. It consists of a small
induction coil that can be constructed at home.

The core of the coil, A, Fig. 1, is constructed in the usual
manner, of small soft-iron wire to make a bundle about 3/16 in. in
diameter and 2 in. long. The coil ends are made from cardboard,
about 1 in. in diameter, with a 3/16-in. hole in the center. The
hole

[Illustration: Details of Induction Coil]

should be cut as shown in Fig. 2, so as to have four small pieces
that can be bent out, leaving the projections as shown. After
wrapping three or four turns of paper around the bundle of wires
the cardboard ends are put on with the projections inside, so the
coils of wire will hold them in place. About 70 turns of No. 24
gauge double covered magnet wire is first placed on the core, for
the primary, and then 1,500 turns of No. 32 or 34 gauge
double-covered wire is wrapped on top of the primary, for the
secondary. Sufficient length of wire must be left outside at each
end of both windings to make connections. The vibrator B, Fig. 1,
and the support C are made from thin spring steel, about 1/8 in.
wide, bent as shown and securely fastened to the cardboard end of
the coil. The armature is made from a soft piece of iron, about
3/16 in. in diameter and 1/16 in. thick, which is soldered to the
end of the vibrator directly opposite the end of the core. A small
screw is fitted in the end of the support, C, for adjustment,
which should be tipped with platinum and also a small piece of
platinum placed where the screw will touch the vibrator, B.

One of the primary wires is connected to the screw support. The
vibrator, is connected to a flash lamp battery, D. The other
primary wire is connected to a switch, S, which in turn is
connected to the other terminal of the battery. The switch, S, may
be made from a 3/8-in. cork with the wires put through about 3/16
in. apart and allow them to project about 1/2 in. The plate E is
cut about 1/2 in. square from a piece of copper and is fastened to
the heel of one shoe and connected with a wire from the secondary
coil which must be concealed inside of the trouser leg. The other
secondary wire is connected through the coat sleeve to a finger
ring, F. The vibrator screw must be properly adjusted. When the
vibrator is not working the armature should be about 1/16 in. from
the core and directly opposite.

The coil when complete will be about 2-1/2 in. long and 1 in. in
diameter. The coil can be placed in an old box that has been used
for talcum powder or shaving stick. The space around the coil in
the box can be filled with paper to keep it tight.

The coil and battery are carried in the pockets and the cork
button put in the outside coat pocket, where it can be pressed
without attracting attention.



** Experiment with Heat [134]

[Illustration: Heat Experiment]

Place a small piece of paper, lighted, in an ordinary water glass.
While the paper is burning turn the glass over and set into a
saucer previously filled with water. The water will rapidly rise
in the glass, as shown in the sketch.



** How to Attach a Combination Trunk Lock [134]

[Illustration: Trunk Lock]

A small combination lock for chests can be purchased for a small
sum of money and attached to a trunk cover after first removing
the old lock as shown in Fig. 1. It is necessary to add 1/2-in. to
the thickness of the trunk lid or cover. This may be done by
placing a brass plate 1/8-in. thick on the outside and a board
3/8-in. thick on the inside. The lock, brass plate, board and
trunk cover are all securely riveted together. The support for the
dial is soldered to the brass plate.

The hasp, if that be the name for the double toothed arrangement
that catches into the lock, was to be secured by only three brass
screws, which seemed to be insufficient, says a correspondent of
the Metal Worker; therefore a piece of heavy tin was formed over
the front of the trunk, which is only 3/8-in. board, the hasp
tinned and soldered to the back of the now U-shaped tin, and the
tin placed over the board and all fastened in position. The tin is
4 in. wide, 16 in. long and when placed over the board, it laps
down about 8 in. between the boards, and the same distance inside
of the new board, as shown by the heavy line in the cross section,
Fig. 1. Wrought nails are used which pass twice through the tin
and both boards, and then well clinched. The three screws were
then put in the hasp.

The knob on the dial extends out too far, which may be filed off
and two holes substituted, as shown, with which to operate the
dial. An old key is filed down in the shape shown in Fig. 2 to fit
the two holes.

As the dial is convex it will need protection to prevent injury by
rough handling. A leather shield may be used for this purpose,
which is cut with two holes, one for the key and the other to
permit the operator to observe the numbers on the dial. The shield
answers a further purpose of preventing any bystander from noting
the numbers on the dial.



** AN ELECTRIC ILLUSION BOX [135]

The accompanying engravings show a most interesting form of
electrically operated illusion consisting of a box divided
diagonally and each division alternately lighted with an electric
lamp. By means of an automatic thermostat arranged in the lamp
circuit causing the lamps to light successively, an aquarium
apparently without fish one moment is in the next instant swarming
with live gold fish; an empty vase viewed through the opening in
the box suddenly is filled with flowers, or an empty cigar box is
seen and immediately is filled with cigars.

These electric magic boxes as shown are made of metal and oxidized
copper finished, but for ordinary use they can be made of wood in
the same shape and size. The upper magic boxes as are shown in the
engraving are about 12 in. square and 8-1/2 in. high for parlor
use and the lower boxes are 18 in. square and 10-1/2 in. high for
use in window displays. There is a partition arranged diagonally
in the box as shown in the plan view, which completely divides the
box into two parts. One-half the partition is fitted with a plain,
clear glass as shown. The partition and interior of the box are
rendered non-reflecting by painting with a dull, not shiny, black
color. When making of wood, a door must be provided on the side or
rear to make changes of exhibits. If the box is made large enough,
or in the larger size mentioned, openings may be made in the
bottom for this purpose, and also used in case of performing the
magic trick of allowing two persons to place their

[Illustration: Construction of Magic Boxes]

heads in the box and change from one to the other.

The electric globes are inserted as shown at LL through the top of
the box, one in each division. When the rear part is illuminated,
any article arranged within that part will be visible to the
spectator looking into the box through the front opening, but when
the front part is illuminated, and the back left dark, any article
placed therein will be reflected in. the glass, which takes the
same position to the observer as the one in the rear. Thus a plain
aquarium is set in the rear part and one with swimming fish placed
in

[Illustration: Four Electric Magic Boxes Complete for Use]

the front, and with the proper illumination one is changed, as it
appears, into the other. When using as a window display, place the
goods in one part and the price in the other. Many other changes
can be made at the will of the operator.

Electric lamps may be controlled by various means to produce
different effects. Lamps may be connected in parallel and each
turned on or off by means of a hand-operated switch or the button
on the lamp socket, or if desired a hand-operated adjustable
resistance may be included in the circuit of each lamp for
gradually causing the object to fade away or reappear slowly.

Instead of changing the current operated by hand, this may be done
automatically by connecting the lamps in parallel on the lighting
circuit and each connected in series with a thermostatic switch
plug provided with a heating coil which operates to automatically
open and close the circuit through the respective lamp.

When there is no electric current available, matches or candles
may be used and inserted through the holes H, as shown in the
sketch, alternately.



** Replace Dry Putty [136]

Painting over putty that has not become dry will cause scaling or
cracking around the edges of the putty.



** Photo Print Washing Tank [136]

The accompanying sketch shows a simple form of a print washing
tank that tips from side to side by the weight of the water. For
prints 4 by 5 and 5 by 7-in. a tank 2 ft. long and 1 ft. wide will
be about the right size. This tank is then divided with a
partition placed exactly in the center. This partition should
extend 3 or 4 in. above the top of the tank. The partition may
also extend below the tank about 1-1/2 in., or a piece of this
width put on the bottom, as shown at A in the sketch.

[Illustration: Keeps Prints Constantly Moving]

A row of holes about 1/2 in. in diameter is bored through each end
of the tank, as shown at B. These holes will allow the water to
spill out while the opposite side is filling. The tank may be made
from 1/2-in. material and when completed as shown, lined with oil
cloth to make it watertight. The tank is placed with the partition
directly under a water tap and the flow of water will cause it to
tip from time to time, keeping the prints constantly moving about
in the water.



** Home-Made Soldering Clamps [137]

Take a cotter pin and bend it over a small rod to bring the points
together, as shown in the sketch. This will make a spring clamp
that is opened to slip over the articles to be clamped together by
inserting a scratch awl or scriber between the legs at the bowed
portion. To make a more positive clamp before bending the legs to
a bow, slip a short coil of wire over the pin, passing it down to
the ring end. Wire 1/32 in. in diameter wound over a wire slightly
larger in diameter than that of the cotter will do. In soldering,
smoke the legs well to avoid solder adhering to them. The clamp is
tightened by pushing up the coil ring toward the bow of the legs
and then twisting it like a nut, the coil being wound
right-handed, so that it will have a screw effect.

[Illustration: Clamp]



** A Telephone Experiment [137]

If the small apparatus, as shown in the accompanying sketch, is
attached to the under side of an ordinary dining table, it will,
if connected to a telephone circuit, set the table in vibration,
so that any number of people who put their ears flat upon the
table will hear the voice of a person speaking from a distance,
apparently coming out of the table, says the Model Engineer. A
small piece of wood, A, Fig. 1, is cut about 5 in. square, to the
center of which is attached a small piece of soft iron wire, such
as used for cores

[Illustration: Mechanical Table Talk]

of induction coils, about 4 in. long and bent in the form of a
hook at the lower end, as shown at B. This wire is attached to the
block of wood, A, as shown in Fig. 2. The end of the wire is
soldered to a small brass plate which is set in the block so it
will be level or flush with the top of the block and then fastened
with two screws. The block A is fastened to the under side of the
table with two screws. A small coil, C, is made by winding No. 24
silk or cotton covered wire around a small tube, either a piece of
glass, a short straw or a quill. The coil is made tapering as
shown without using wood ends. This coil is slipped over the wire
B previous to soldering it to the small brass plate. The ends of
the coil are connected to two binding-posts which are fastened to
the block A. A small lead weight weighing 2 or 3 oz. is hung on
the hook made in the lower end of the wire B.

When all connections are made, as shown in Fig. 1, and the block
fastened to the under side of the table, the apparatus is ready
for use, and has only to be connected to an ordinary telephone
transmitter and batteries as shown. The apparatus will work to a
certain extent even if the weight is removed, though not so clear.



** Wax Wood Screws [137]

Some workmen use tallow on lag or wood screws. Try beeswax for
this purpose. It is much cleaner to use and is just as good if not
better.



** How to Make an Induction Coil [138]

A small shocking coil, suitable for medical purposes, may be
constructed of materials found in nearly every amateur mechanic's
collection of odds and ends. The core, A, Fig. 1, is a piece of
round soft iron rod about 1/4 in. in diameter and about 4 in.
long. A strip of stiff paper about 3/4 in. wide is covered with
glue and wrapped around one end of the core, as shown at B, until
the diameter is about 3/8 in. The portion of the core remaining
uncovered is then wrapped with a piece of paper about 4 in. wide.
No glue is used on this piece, as it is removed later to form the
space, C, after the paper shell, D, has been wound upon it. This
paper shell is made of stiff paper and glue the same as B and is
made about 3/64 in. thick. Two pieces of hardwood, EE, 1-3/4 in.
square and about 5/16 in. thick, are drilled in the center and
glued on the ends of the paper shell as shown.

The primary winding consists of 4 or 5 layers of No. 18 or 20
single cotton-covered magnet wire, the ends of which may be passed
through small holes in the wooden ends. If a drill small enough is
not available, the holes may be made with a hot knitting needle or
a piece of wire heated to redness. After the primary coil is wound
it should be thoroughly insulated before winding the secondary.
This may be done by wrapping with 4 or 5 thicknesses of paper.

The secondary coil should be wound with single covered wire,
preferably silk-covered, although cotton will do. The more turns
there are on the secondary the higher the voltage will be, so the
wire used must be fine. Number 32 to 36 will give good results,
the latter giving more voltage but less amperage. Each layer of
the secondary winding should be insulated from the others by a
piece of thin paraffined paper wrapped over each layer as it is
finished. It is well not to wind to the extreme ends of the paper
insulations, but to leave a space of about 1/8-in. at each end of
the winding to prevent the wires of one layer slipping over the
ends of the paraffin

[Illustration: Induction Coil]

paper and coming in contact with the layer beneath, thus causing a
short circuit. The secondary winding should have at least a dozen
layers and should be carefully wound to prevent short circuiting.

In order to reduce the strength of the current a piece of brass
tubing, F, is pushed into the space, C, surrounding the core, or
if no brass tubing of the required size is on hand, roll a paper
tube, cover with 4 or 5 thicknesses of tinfoil and then wrap with
more paper, using glue to hold the tinfoil in place and to keep
the tube from unwinding. When the tube is pushed all the way in,
the current produced

[Illustration: Induction Coil]

will be almost unnoticeable, but when it is withdrawn the current
will be so strong that a person cannot let go the handles until
the coil is shut off. After the secondary coil is wound it should
be covered with stiff paper, and the whole coil, including the
wood ends, should then be enameled black.

It is then ready to be mounted on a wooden base as shown in Fig.
2. The secondary terminals are connected to the binding-posts, AA,
which may be fastened on the base if desired. One wire from the
primary is connected with the binding-post, B, and the other is
connected with the armature, D, which may be taken from an old
electric bell. The contact screw, E, also from an electric bell,
is connected to the binding-post, C. The contact spring, F, should
be bent against and soldered to the armature in order to make the
vibrations more rapid.

If a false bottom is used on the base, all the wiring may be
concealed, which adds greatly to the appearance and if desired a
small switch may be added. The handles, which may be old bicycle
pumps or electric light carbons, are connected to the
binding-posts, AA, by means of wires about 3 or 4 ft. long. This
coil when operating with the tube pulled all the way out and
connected to a single dry cell will give a current stronger than
most persons can stand.



** Home-Made Toaster [139]

Each outside frame of the toaster is made from one piece of wire
30 in. long. These are bent in a perfect square making each side
7-in. long. This will allow 1 in. on each end for tying by
twisting the ends together. The first two wires inside and on each
side of each frame are 8 in. long. Eight wires will be required
for this purpose and as they are 8 in. long 1/2 in. is allowed on
each end for a bend around the outside frame, as shown in the
sketch. The two middle wires are extensions of the handles. Each
of these wires are made from a piece about 26 in. long and bent in
the shape of a U. The ends of the wire are bent around the frame
in the same manner

[Illustration: Toaster]

as the other wires. This will leave the handle laying across the
other side of the frame. The frame is fastened to the handle on
this side by giving the handle one turn around the frame. The
inside edges of the frame are now tied together with a small ring
of wire which is loose enough to allow each half to swing freely.
--C. D. M.



** Home-Made Shocking Machine [139]

An ordinary electric bell may be connected up in such a way as to
produce the same results as an expensive

[Illustration: Inexpensive and Effectual]

shocking machine. The connections are made from the batteries to
the bell in the usual manner. Two other wires are then connected,
one to the binding-post of the bell that is not insulated from the
frame and the other to the adjusting screw on the make and break
contact of the bell as shown in the sketch. The other ends of the
wires are connected each to a common table knife. This will give
quite a good shock and a much larger one can be had by placing one
knife in a basin of water and while holding the other knife in one
hand, dipping the fingers of the other hand in the water.
--Contributed by D. Foster Hall.



** Mahogany Wood Putty [139]

Mix venetian red with quite thick arabic muscilage, making it into
a putty, and press this well into the cracks of mahogany before
finishing. The putty should be colored to suit the finish of the
wood, says the Master Painter, by adding such dry color to the gum
as will give the best result.



** How to Make a Thermoelectric Battery [140]
By Arthur E. Joerin

A novel way of producing an electric current by means of hot and
cold water, heat from a match or alcohol

[Illustration: Details of Battery]

lamp, is obtained from a device constructed as shown in the
sketch. Take two hardwood boards, marble, or slate plates, about 8
or 10 in. long, place them together, as in Fig. 1, and mark and
drill about 500 holes. These two pieces should be separated about
8 in. and fastened with boards across the ends, as shown in Fig.
2.

Take soft copper wire, not smaller than No. 18 gauge, and cut in
lengths to pass through the holes in the two boards, leaving
sufficient end to make a tie. It will require about 70 ft. of wire
to fill one-half the number of holes. Also, cut the same number of
lengths from the same gauge galvanized-iron wire to fill the
remaining holes. The wires are put through the holes in the boards
alternately, that is: begin with copper, the next hole with iron,
the next copper, the next iron, and so on, twisting the ends
together as shown in Fig. 3. The connections, when complete,
should be copper for the first and iron for the last wire.

When the whole apparatus is thus strung, the connections, which
must be twisted, can be soldered. Connect one copper wire to the
bell and the other terminal, which must be an iron wire, to the
other post of the bell. The apparatus is then short-circuited, yet
there is no current in the instrument until a lighted match, or,
better still, the flame of an alcohol lamp is placed at one end
only.

Best results are obtained by putting ice or cold water on one side
and a flame on the other. The experimenter may also place the
whole apparatus under sink faucets with the hot water turned on at
one terminal and the cold water at the other. The greater the
difference of temperature in the two terminals, the more current
will be obtained.

Very interesting experiments may thus be performed, and these may
lead to the solving of the great thermoelectric problem.



** How to Make a Hygrometer [140]

Mount a wire on a board which is used for a base and should be 3/8
by 4 by 8 in., as shown in the sketch. A piece of catgut--a string
used on a violin will do--is suspended from the bent end of the
wire. A hand or pointer is cut from a piece of tin and secured to
the catgut string about 1/2 in. from the base. A small piece of
wood and some glue will fasten the pointer to the string. The
scale is

[Illustration: Simple Hygrometer]

marked on a piece of cardboard, which is fastened to the base and
protected with a piece of glass.
--Contributed by J. Thos. Rhamstine.



** Softening Leather in Gloves and Boots [140]

The leather in high-top boots and gauntlet gloves may be softened
and made waterproof by the use of plain mutton tallow. Apply hot
and rub in well with the fingers.



** How to Make a Mission Library Table [141]

The mission library table, the drawings for which are here given,
has been found well proportioned and of pleasing appearance. It
can be made of any of the several furniture woods in common use,
such as selected, quarter-sawed white oak which will be found
exceptionally pleasing in the effect produced.

If a planing mill is at hand the stock can be ordered in such a
way as to avoid the hard work of planing and sandpapering. Of
course if mill-planed stock cannot be had, the following
dimensions must be enlarged slightly to allow for "squaring up the
rough."

For the top, order 1 piece 1-1/8 in. thick, 34 in. wide and 46 in.
long. Have it S-4-S (surface on four sides) and "squared" to
length. Also, specify that it be sandpapered on the top surface,
the edges and ends.

For the shelf, order 1 piece 7/8 in. thick, 22 in. wide and 42 in.
long, with the four sides surfaced, squared and sandpapered the
same as for the top.

For the side rails, order 2 pieces 7/8 in. thick, 6 in. wide and
37 in. long, S-4-S and sanded on one side. For the end rails, 2
pieces 7/8 in. thick, 6 in. wide and 25 in. long. Other
specifications as for the side rails.

For the stretchers, into which the shelf tenons enter, 2 pieces
1-1/8 in. thick,

[Illustration: This Picture Is from a Photograph of the Mission
Table Described]

3-3/4 in. wide and 25 in. long, surfaced and sanded on four sides.
For the slats, 10 pieces 5/88 in. thick, 1-1/2 in. wide and 17 in.
long, surfaced and sanded on four sides. For the keys, 4 pieces
3/4 in. thick, 1-1/4 in. wide and 2-7/8 in. long, S-4-S. This
width is a little wide; it will allow the key to be shaped as
desired.

The drawings obviate any necessity for going into detail in the

[Illustration: Table Details]

description. Fig. 1 gives an assembly drawing showing the relation
of the parts. Fig. 2 gives the detail of an end. The tenons for
the side rails are laid off and the mortises placed in the post as
are those on the end. Care must, be taken, however, not to cut any
mortises on the post, below, as was done in cutting the stretcher
mortises on the ends of the table. A good plan is to set the posts
upright in the positions they are to occupy relative to one
another and mark with pencil the approximate positions of the
mortises. The legs can then be laid flat and the mortises
accurately marked out with a fair degree of assurance that they
will not be cut where they are not wanted and that the legs shall
"pair" properly when effort is made to assemble the parts of the
table.

The table ends should be glued up first and the glue allowed to
harden, after which the tenons of the shelf may be inserted and
the side rails placed.

There is a reason for the shape, size and location of each tenon
or mortise. For illustration, the shape of the tenon on the top
rails permits the surface of the rail to extend almost flush with
the surface of the post at the same time permitting the mortise in
the post to be kept away from that surface. Again, the shape of
the ends of the slats is such that, though they may vary slightly
in length, the fitting of the joints will not be affected. Care
must be taken in cutting the mortises to keep their sides clean
and sharp and to size.

In making the mortises for the keyed tenons, the length of mortise
must be slightly in excess of the width of the tenon--about
1/8-in. of play to each side of each tenon. With a shelf of the
width specified for this table, if such allowance is not made so
that the tenons may move sideways, the shrinkage would split the
shelf.

In cutting across the ends of the shelf, between the tenons, leave
a hole in the waste so that the turning saw or compass saw can be
inserted. Saw within one-sixteenth of the line, after which this
margin may be removed with chisel and mallet.

In Fig. 3 is shown two views of the keyed tenon and the key. The
mortise for the key is to be placed in the middle of the tenon. It
will be noted that this mortise is laid out 1-1/16 in. from the
shoulder of the tenon while the stretcher is 1-1/8 in. thick. This
is to insure the key's pulling the shelf tightly against the side
of the stretcher.

Keys may be made in a variety of shapes. The one shown is simple
and structurally good. Whatever shape is used, the important thing
to keep in mind is that the size of the key and the slant of its
forward surface where it passes through the tenon must be kept the
same as the mortise made for it in the tenon.

The top is to be fastened to the rails by means either of wooden
buttons, Fig. 4, or small angle irons.

There are a bewildering number of mission finishes upon the
market. A very satisfactory one is obtained by applying a coat of
brown Flemish water stain, diluted by the addition of water in the
proportion of 2 parts water to 1 part stain. When this has dried,
sand with number 00 paper, being careful not to "cut through."
Next, apply a coat of dark brown filler; the directions for doing
this will be found upon the can in which the filler is bought. One
coat usually suffices. However, if an especially smooth surface is
desired a second coat may be applied in a similar manner.

After the filler has hardened, a very thin coat of shellac is to
be put on. When this has dried, it should be sanded lightly and
then one or two coats of wax should be properly applied and
polished. Directions for waxing are upon the cans in which the wax
is bought. A beautiful dull gloss so much sought by finishers of
modern furniture will be the result of carefully following these
directions.



** A Hanger for Trousers [143]

Secure two clothes pins of the metal spring kind for the clamps of
the hanger. The pins are fastened one to each end of a looped
galvanized wire. This wire should be about 6 in. long after a coil
is bent in the center as shown in the sketch. The diameter of the
wire should be about 1/8 in.

[Illustration: Hanger]



** How to Make an Adjustable Negative Washer [143]

The sketch herewith shows a washing box for negatives made from an
ordinary wooden box. As can be seen, the grooved partition, A, is
removable, and as several places are provided for

[Illustration: Washing Box]

its insertion, the tank can be made to accommodate anyone of
several sizes of plates, says Camera Craft. The other stationary
partition, B, which does not reach quite to the bottom of the
tank, is placed immediately next to the end of the tank, leaving a
channel between the two for the inflow of the wash water. A
narrow, thin strip, C, is fastened to the bottom of the tank to
keep the plates slightly raised, at the same time allowing a
clearer flow of the water from the bottom upwards to the
discharge.

The water enters the narrow partition at the end, flows under the
partitions B and A, then upward between and parallel to the
surface of the plates, escaping at the opposite end over the top
of the tank end, in which the upper part has been cut away for
that purpose. The depth of this cut, in the upper part of the tank
end, should allow the overflow to be a trifle higher than the
width of the largest size plate for which the tank is fitted.
Partition B being stationary, can be nailed in position
permanently, allowing the bottom edge to clear the bottom of the
tank the desired distance. Partition A being movable should have
attached to its bottom edge a couple of nails, D, or better still,
wooden pegs, which will keep it also above the bottom of the tank
at the desired height.

A coat of paraffin paint should be applied, and, just before it
sets perfectly hard, any rough spots trimmed down with a knife or
chisel and a second lighter coat applied. If the wood is very dry
and porous a preliminary coat of the paint should be applied and
allowed to soak into the pores. It is also well to apply a coat of
the paint to the joints at the corners and around the edge of the
bottom before nailing together.



** Turn-Down Shelf for a Small Space [144]

The average amateur photographer does not have very much space in
which to do his work. The kitchen is the room used ordinarily for
finishing the photographs. In many instances there will not be
space enough for any extra tables, and so a temporary place is
prepared from boxes or a chair on which to place the trays and
chemicals. Should there be space enough on one of the walls a
shelf can be made to hang down out of the way when not in use. A
shelf constructed on this order may be of any length to suit the
space or of such a length for the purpose intended. A heavy piece
of wood, about

[Illustration: Turn Down Shelf]

1-1/2 in. thick, and 4 to 6 in. wide, is first fastened to the
wall at the proper height with nails, or, much better, large
screws.

The shelf is cut and planed smooth from a board 12-in. wide and
about 1-in. thick. This board is fastened to the piece on the wall
with two hinges as shown in Fig. 1. A small cleat is nailed to the
outer and under edge of the board and in the middle as shown. This
is used to place a support under the outer edge of the shelf. The
support, A, Fig. 2, should be long enough to extend diagonally to
the floor or top of the baseboard from the inner edge of the cleat
when the shelf is up in its proper place. --L. L.



** Home-Made Electric Battery Massage [144]

A simple and cheap electric massage device can be made by using
three or

[Illustration: Electric Massage]

four cells of dry battery connected to two ordinary silver
tablespoons, as shown in the sketch. The handles of the spoons
should be insulated or the operator can wear either kid or rubber
gloves.



** How to Make Tint Lantern Slides [144]

Purchase some lantern slide plates and fix them in hypo without
exposing, in the usual manner, same as you would an exposed plate,
says the Moving Picture World. This leaves a thin, perfectly
transparent emulsion film on the glass, which will readily take
color. Mix a rather weak solution of clear aniline dye of the
desired color and dip the plate in it, wiping the plate side
clean. If not dark enough, dip again and again until desired tint
is attained, letting it dry between each dipping. A very light
blue tint slide will brighten a yellow film considerably, but the
tint must be very light, just a bare tint.



** A Bicycle Catamaran [145]

The accompanying photographs show a bicycle boat made to carry two
persons.

[Illustration: This Catamaran Carries Two People]

This boat is constructed by using two galvanized iron tubes 18 ft.
long and 12 in. in diameter, tapered at the front end down to
cast-iron points, and the rear end shaped to attach rudders. These
tubes are placed 26 in. apart, giving the boat an extreme width of
50 in.

The cylinders support a platform and on the rear end of this
platform is constructed a paddle wheel 52 in. in diameter with 16
spokes. On the end of each spoke is fastened a galvanized sheet
metal blade 6 in. wide and 8 in. long. A large guard placed over
the paddle wheel forms a seat for one person and a chair in front
on the platform provides a place for a second person.

The person in front helps to propel the boat with hand levers
which are connected with rods to sprocket wheels on each side of
the platform. The occupant of the rear seat contributes his part
of the power with his feet on pedals of the shaft that carries the
sprocket wheels. This shaft and sprocket wheels drive the paddle
wheel by side chains of the bicycle kind. The boat is steered from
the rear seat by ropes attached to double rudders. This boat will
run at considerable speed and is very steady in rough water as it
goes directly through large waves instead of going over them.
--Contributed by Ernest Schoedsack, Council Bluffs, Iowa.



** How to Make a Lead Pencil Rheostat [145]

Take an ordinary lead pencil and cut seven notches at equal
intervals on the pencil down to and around the lead, leaving it
bare. A seven-point switch is constructed on a board of suitable
size making the points by using screws that will go through the
board. A small piece of tin or brass will do for a switch and is
fastened as shown. The connections are made on the back side of
the board as shown by the dotted lines. This will reduce 40 to 50
volts down to 5 or 10 volts for short lengths

[Illustration: Simple Rheostat]

of time.
--Contributed by Roy Newby, San Jose, Cal.



** Homemade Shoe Rack [146]

The accompanying sketch explains how a boy can make his own shoe
rack that can be placed on the wall in

[Illustration: Shoe Rack]

the clothes closet. Figure 1 shows the construction of the bottom
to permit the dirt to fall through. Two boards, 9 in. wide and
about 3 ft. long, with six partitions between, as shown, will make
pockets about 6 in. long. The width of the pockets at the bottom
is 2 in. and at the top 5 in.
--Contributed by Guy H. Harvey, Mill Valley, Cal.



** How to Waterproof Canvas [146]

The method used by the British navy yards for waterproofing and
painting canvas so it will not become stiff and cracked is as
follows: One ounce of yellow soap and 1/2 pt. of hot water are
mixed with every 7 lb. of paint to be used. The mixture is applied
to the canvas with a brush. This is allowed to dry for two days
and then a coat of the same paint, without the soap, is laid on.
When this last coat is dry the canvas may be painted any color
desired. After three days of drying the canvas may be folded up
without sticking together, and is, of course, waterproof. Canvas
waterproofed in this manner makes an excellent covering for
portable canoes and canvas boats. The color mixture for the soap
and second application is made from 1 lb. of lampblack and 6 lb.
of yellow ocher, both in oil; the finish coat may be any color
desired. When no paint is to be used on the canvas it may be
waterproofed with a mixture made from soft soap dissolved in hot
water, and a solution of iron sulphate added. Iron sulphate, or
ferrous sulphate, is the green vitriol. The vitriol combines with
the potash of the soap, and the iron oxide is precipitated with
the fatty acid as insoluble iron soap. This precipitate is then
washed, dried and mixed with linseed oil.



** Building a House in a Tree Top [146]

The accompanying photograph shows a small house built in a tree
top 20 ft. from the ground. The house is

[Illustration: Lofty Sentry Box for Guarding Watermelon Patch]

5 ft. wide, 5 ft. 1 in. long, and 6 ft. 6 in. high. A small
platform, 2 ft. wide, is built on the front. Three windows are
provided, one for each side, and a door in front. The entrance is
made through a trap door in the floor of the house. This house was
constructed by a boy 14 years old and made for the purpose of
watching over a melon patch.
--Contributed by Mack Wilson, Columbus, O.



** How to Make a Lamp Stand and Shade [147]

A library light stand of pleasing design and easy construction is
made as follows: Square up a piece of white oak so that it shall
have a width and thickness of 1-3/4 in. with a length of 13 in.
Square up two pieces of the same kind of material to the same
width and thickness, but with a length of 12 in. each. Square up
two pieces to a width and length of 3 in. each with a thickness of
1-1/8 in.

If a planing mill is near, time and patience will be saved by
ordering one piece 1-3/4 in. square and 40 in. long, two pieces
1-1/8 in. thick and 3 in. square, all planed and sandpapered on
all surfaces. The long piece can then be cut at home to the
lengths specified above.

The 13-in. piece is for the upright and should have a 1/2-in. hole
bored the full length through the center. If the bit is not long
enough to reach entirely through, bore from each end, then use a
red-hot iron to finish. This hole is for the electric wire or gas
pipe if gas is used.

The two pieces for the base are alike except the groove of one is
cut from the top and of the other from the under side, as shown.
Shape the under sides first. This can best be done by placing the
two pieces in a vise, under sides together, and boring two holes
with a 1-in. bit. The center of each hole will be 2-1/2 in. from
either end and in the crack between the pieces. The pieces can
then be taken out, lines gauged on each side of each, and the wood
between the holes removed with turning saw and scraper steel.

The width of the grooves must be determined by laying one piece
upon the other; a trysquare should be used to square the lines
across the pieces, however, gauge for depth, gauging both pieces
from their top surfaces. Chisel out the grooves and round off the
corners as shown in the sketch, using a 3/4-in. radius.

These parts may be put together and fastened to the upright by
means of two long screws from the under side, placed to either
side of the 1/2-in. hole. This hole must be continued through the
pieces forming the base.

The braces are easiest made by taking the two pieces which were
planed to 1-1/8 in. thick and 3 in. square and drawing a diagonal
on each. Find the middle of this diagonal by drawing the central
portion of the other diagonal; at this point place the spur of the
bit and bore a 1-in. hole in each block.

Saw the two blocks apart, sawing

[Illustration: Details of Construction of Library Lamp Stand]

along a diagonal of each. Plane the surfaces on the saw cut smooth
and sandpaper the curve made by the bit. Fasten the braces in
place by means of roundhead blued screws.

To make a shade such as is shown in the illustration is rather
difficult. The shade is made of wood glued up and has art glass
fitted in rabbets cut on the inner edges. Such shades can be
purchased ready to attach. The sketch shows one method of
attaching. Four small pieces of strap iron are bent to the shape
shown and fastened to the four sides of the upright. Electric
globes--two, three or four may be attached as shown.

The kind of wood finish for the stand will depend upon the finish
on the wooden shade, if shade is purchased. Brown Flemish is
obtained by first staining the wood with Flemish water stain
diluted by the addition of two parts water to one part stain. When
this is dry, sandpaper the "whiskers" which were raised by the
water and fill with a medium dark filler. Directions will be found
on the filler cans. When the filler has hardened, apply two coats
of wax.

The metal shade as shown in the sketch is a "layout" for a copper
or brass shade of a size suitable for this particular lamp. Such
shades are frequently made from one piece of sheet metal and
designs are pierced in them as suggested in the "layout." This
piercing is done by driving the point of a nail through the metal
from the under side before the parts are soldered or riveted
together. If the parts are to be riveted, enough additional metal
must be left on the last panel to allow for a lap. No lap is
needed when joints are soldered.

A better way, and one which will permit the use of heavier metal,
is to cut each side of the shade separately and fasten them
together by riveting a piece of metal over each joint. The shape
of this piece can be made so as to accentuate the rivet heads and
thus give a pleasing effect.

For art-glass the metal panels are

[Illustration: The Completed Lamp]

cut out, the glass is inserted from the under side and held in
place by small clips soldered to the frame of the shade. Pleasing
effects are obtained by using one kind of metal, as brass, and
reinforcing and riveting with another metal, such as copper.

[Illustration: METAL SHADE--Construction of Shade]



** Illuminating a Watch Dial at Night [149]

This picture shows a watch holder, with a device to receive an
ordinary electric pocket lamp and battery. The battery is set in a
bracket under which a reflector extends downward to throw the
light on the dial of the watch and to protect the eyes from the
direct light. The entire stand and bracket are made from sheet
metal. The base is formed to make a tray to hold pins and collar
buttons. It is not necessary to seek in the darkness for a push
button or switch, as in ordinary devices, but a light pressure
with the palm of the hand will make the lamp glow.

[Illustration: Lamp]



** Home-Made Photographic Copying Stand [149]

The difficulties of bad lighting on small articles can be entirely
avoided by the use of a suitable support for the camera, the
object and the background.

[Illustration: Secures Good Light on Small Objects]

For illustrations it is often an advantage to show an object with
a perfectly plain background and no deep shadows. When using the
stand as illustrated this is a very simple matter. Figure 1 shows
the side, and Fig. 2 the front view of this stand. The stand is
very easily constructed from pipe and pipe fittings. The main pipe
of the stand will need to be of proper length to suit the focus of
your camera. This can be determined by finding the length from the
lens to the object after the bellows are extended to their full
length. The arms holding the glass, as shown in the sketch, should
be set at a point about the middle of the main tube. The cross
that holds the middle arms should be 3/4 in. one way and 1/2 in.
the other. This will allow for adjustment of the glass table. A
small set screw provided in the back of this cross will hold the
table in any position desired. The pipes and other connections are
all 1/2-in. and the lengths of the pipes are made suitable for the
size of the camera. When a small object is to be photographed it
is placed upon the glass table and the background fastened to the
board. In this manner small objects can be photographed without
any deep shadow on one side. The bottom cross and ells should be
corked so as to prevent any slipping and damage to the floor.



** Home-Made Pocket Lamp [149]

A simple and safe pocket lamp that will last for about 6 months
without extra expense can be made at home for a few cents.

Have your druggist take a strong vial of clear glass, or a pill
bottle with screw or cork top and put into it a piece of
phosphorus about the size of a pea and fill the bottle one-third
full of pure olive oil that has been heated for 15 minutes--but
not boiled. Cork tightly and the result will be a luminous light
in the upper portion of the bottle. If the light becomes dim,
uncork and recork again. The lamp will retain its brilliancy for
about 6 months. This makes a perfectly safe lamp to carry. These
lamps are used by watchmen of powder magazines. Care should be
exercised in handling the phosphorus, as it is very poisonous.



** How to Make a Tangent Galvanometer [150]

Secure a piece of wood 1/2 in. thick and cut out a ring with an
outside diameter of 10-1/2 in. and an inside diameter of 9 in. and
glue to each side two other rings 1/4 in. thick with the same
inside diameter as the first ring and 11 in. outside diameter,
thus forming a 1/4-in. channel in the circumference of the ring.
If a lathe is at hand this ring can be made from a solid piece and
the channel turned out. Cut another circular piece 11 in. in
diameter for a base. Make a hole in the center of this piece 1 in.
wide and 6-5/16 in. long, into which the ring first made should
fit so that its inner surface is just even with the upper surface
of the baseboard. The ring is held upright in the hole by a small
strip screwed to the base as shown. All screws and brads that are
used must be of brass. The cutting of these circular pieces is not
so difficult if a band saw driven by power is used. They can be
cut by means of a key-hole saw if a band saw is not accessible.

Before mounting the ring on the base, the groove should be wound
with 8 turns of No. 16 double cotton-covered magnet wire. The two
ends may be tied together with a string to hold them temporarily.

Fasten two strips of wood 1/4-in. thick 5/8-in. wide and 11 in.
long across the sides of the ring with their upper edges passing
exactly through the center of the ring. An ordinary pocket
compass, about 1-1/4 in. in diameter, is fitted in these strips so
that the center of the needle or pointer will be exactly in the
center of the ring and its zero point mark at the half-way point
between the two strips. Put the ring in place on the base, as
shown in the sketch, and connect the two ends of the wire to two
binding-posts that are previously attached to the base. Coat the
entire surface with brown shellac. Any deviation from the
dimensions will cause errors in the results obtained by its use.

Remove all pieces of iron or steel and especially magnets in the
near vicinity of the instrument when in use. Place the
galvanometer on a level table and turn it until the needle,
pointing north and south, and swinging freely, lies exactly in the
plane of the coil, as shown in the cut. The needle then will point
to zero if the directions have been followed closely. Connect one

[Illustration: Tangent Galvanometer]

cell of battery to the instrument and allow the current to flow
through the coils. The needle of the compass will be deflected to
one side or the other, and will finally come to rest at a certain
angle-let us say 45 deg. The dimensions of the instrument are such
that when the deflection is 45 deg. the current flowing through
the coils upon the ring is 1/2 ampere. The ampere is the unit
chosen to designate the strength of the electric current. For
other angles the value of the current may be found from the
following table:

Angles Degrees  Current Amperes
    10              .088
    20              .182
    30              .289
    40              .420
    45              .500
    50              .600
    55              .715
    60              .865
    70             1.375

As the magnetic force that acts upon a magnet needle varies in
different places the values given for the current will not be true
in all parts of the country. The table gives correct values for
the immediate vicinity of Chicago and that part of the United
States lying east of Chicago, and north of the Ohio river. The
results given should be multiplied by 1.3 for places south of the
Ohio river and east of the Mississippi.



** Home-Made X-Ray Instrument [151]

Two cylinders, AA, are mounted on a base, B, and mirrors, CC, are
fitted at an angle of 45 deg. into these cylinders. Corresponding
mirrors, EE, are put in the base parallel with those in those
cylinders. An opening extends downward from D of each cylinder so
that light entering at one end of the

[Illustration: Details of X-Ray Machine]

cylinder is reflected down at right angles by the first mirror to
the second, from the second to the third, from the third to the
fourth which reflects the light to the eye. Thus the light never
passes through the cylinders and the observer does not see
through, but around any object inserted at X between the
cylinders.



** How to Make a a Non-Polarizing Battery [151]

Bichromate batteries are very expensive to maintain and dry cells
do not furnish enough amperage for some kinds of experimental
work. A cell of a battery that will run 10 hours with an output of
over 1 ampere can be made as follows: Secure a jar about 4 in. in
diameter and 8 in. high and place in the bottom of this jar the
lower half of a tin baking powder can, to which a wire has been
soldered for connections. Place in the can a mixture of 2 oz.
black oxide of copper, 1 oz. black oxide of manganese and some
iron filings.

Purchase a small crowfoot zinc and hang it about 1 in. above the
half can. Prepare a 10 per cent solution of caustic soda and fill
the jar within 1 in. of the top. Place on top the solution a thin
layer of kerosene or paraffin. The cell will only cost about 50
cents to make and 25 cents for each renewal. When renewing, always
remove the oil with a siphon.
--Contributed by Robert Canfield, University Park, Colo.



** A Home-Made Barometer [151]

Take 1/4 oz. of pulverized campor, 62 gr. of pulverized nitrate of
potassium, 31 gr. nitrate of ammonia and dissolve in 2 oz.
alcohol. Put the solution in a long, slender bottle, closed at the
top with a piece of bladder' containing a pinhole to admit air,
says Metal Worker. When rain is coming the solid particles will
tend gradually to mount, little crystals forming in the liquid,
which otherwise remains clear; if high winds are approaching the
liquid will become as if fermenting, while a film of solid
particles forms on the surface; during fair weather the liquid
will remain clear and the solid particles will rest at the bottom.



** Lock Lubricant [151]

A door lock may be lubricated by using some lead scraped from the
lead in a pencil and put in the lock. This may be done by putting
the scrapings on a piece of paper and blowing them into the lock
through the keyhole.



** Rust Proofing Bolts [151]

Where bolts are subject to rust, the threads should be painted
with pure white lead; then they will not rust fast.



** Painting Yellow Pine [151]

When painting yellow pine exposed to the weather add a little pine
tar with the priming coat.



** Revolving a Wheel with Boat Sails [152]

A novel windmill or revolving wheel can be made by placing a light
wheel so it will turn freely on the end

[Illustration: An Unusual Type of Windmill]

of a post, and placing four small sailing boats at equal points on
the rim of the wheel. It makes no difference which way the wind
blows, the wheel will revolve in one direction. In Fig. 1 the
direction of the wind is shown by the arrows, and how the sails
catch the wind and cause the wheel to revolve. Figure 2 shows how
the wheel will appear when complete. This device makes an
attractive advertising sign.



** A Floating Electromagnet [152]

A piece of iron placed in a coil of wire carrying a current of
electricity becomes an electromagnet. If such a coil and iron core
be made small enough they can be attached to a cork and the cork,
floating on a solution, will allow the magnet to point north and
south. The sketch shows how to make such an instrument. A coil of
insulated wire is wrapped around a small iron core, leaving a few
inches of each end free for connections. The insulation is removed

[Illustration: Floating Electromagnet]

from these ends and they are run through a piece of cork. Attach
to the wires, on the under side of the cork, a piece of zinc to
one end and a piece of copper to the other. The cork is then
floated on a solution of acid, with the zinc and copper hanging in
the solution. If zinc and copper are used, the solution is made
from water and blue vitriol. If zinc and carbon are used, the
solution is made from sal ammoniac and water.

The float will move about on the solution until the magnet iron
will point north and south. If two of them are floating on the
same solution, they will move about and finally arrange themselves
end to end with the coils and magnet cores pointing north and
south.
--Contributed by C. Lloyd Enos.



** A Fish Bait [152]

A very effective fish bait is made by inclosing a live minnow in a
short section of glass tube, which is filled with water and both
ends closed with corks. This is used in place of the spoon.



** Homemade Air Thermometer [152]

The illustration shows the complete thermometer. The water in the
glass tube is caused to rise and fall by the expansion and
contraction of the air in the tin box. A paper-fastener box, about
1-1/4 in.

[Illustration: Air Thermometer]

deep and 2 in. in diameter will serve very well for the box A.
Solder in the side of the box 1-in. piece of 1/4-in. brass tubing,
B, and then solder on the cover, C, so that the only escape for
the air is through the brass tube. Secure a piece of 1/4-in. glass
tubing - not shorter than 18 in.--and bend it as shown at D in the
sketch. Hold the part of the tube to be bent in the broad side of
a gas jet, and in a minute or two the tube will bend with its own
weight. Any angle can be given glass tubing in this way. Connect
the glass tube to B with a short piece of rubber hose, E. If the
hose is not a tight fit, bind with a short piece of fine copper
wire. The standard, F, is made from a piece of No. 10 wire about
10 in. long. To this standard solder the supporting wire, G--No.
14 wire will do. On one side bend the wire around the tube B, and
on the other around the glass tube, D.

The base, H, can be made of oak, stained and varnished. The bottom
of the box, A, is covered with lampblack so as to readily absorb
all heat that strikes the surface. The black should not be put on
until just before you paint the supports, cover and rim of the box
with gold or silver paint. Hold the bottom of the box to be
blackened over a little burning cotton saturated with turpentine.

The scale on the glass can be etched with hydrofluoric acid, or
made with a little black paint. The water can be put in with a
medicine dropper. This instrument will measure the amount of heat
given by a candle some 20 or 30 ft. away.
--Contributed by J. Thos. Rhamstine.



** Home-Made Battery Voltmeter [153]

Secure a piece of brass tube 3 in. long that has about 1/4-in.
hole. Put ends, A, 1-1/4 in. square and cut from heavy cardboard
on this tube. Make a hole in the center of each cardboard just
large enough to allow the brass tube to fit tight. Put on two or
three layers of stout paper around the brass tube and between the
cardboard ends. Wind evenly about 2 oz. of No. 26 cotton covered
magnet wire on the paper between the ends and leave about 2 in. of
wire on each end extending from the coil. Use a board 1/2- in.
thick, 3 in. wide and 6 in. long for the base and fasten the coil
to it, as shown in Fig. 1. Bore holes for binding-posts, B, one on
each side of the board, and connect the two wires from the coil to
them. At the other end of the board and in the center drive a wire
nail and attach a small spring, C, to it. The spring should be
about 1 in. long. Take a small piece of soft iron, D, 1/2- in.
long and just large enough to slip freely through the brass

[Illustration: Battery Voltmeter Construction]

tube and solder a piece of copper wire to it; the other end of the
copper wire being hooked to the spring, C. The copper wire must be
just long enough to allow the piece of iron, D, to hang part way
in the end of the coil and still hold the spring in place. A
circular piece of cardboard, E, is slipped over the spring to
where the spring joins the wire. This cardboard is to serve as the
pointer. A piece of paper 1-1/2 in. wide and 2-1/2 in. long is
glued to the board so that it will be directly under the cardboard
pointer and fit snugly up against the top of the coil.

The paper can be calibrated by connecting one cell of battery to
the binding-posts. The iron plunger, D, is drawn into the tube and
consequently the pointer, E, is drawn nearer to the coil. Make a
mark directly under the place where the pointer comes to rest. At
the place mark the number of volts the cell reads when connected
with a voltmeter. Do the same with two or three cells and mark
down the result on the scale. By dividing off the space between
these marks you may be able to obtain a surprisingly correct
reading when connected with the battery cells to be tested.
--Contributed by Edward M. Teasdale, Cuba, N. Y.



** How to Make a Folding Canvas Cot [154]

All the material required to make the cot as shown in Fig. 1
consists of wood 1-1/2 in. square of which two pieces are 6 ft.
long; two pieces 2 ft. 3 in. long; two pieces 2-1/2 ft. long; four
pieces 1-1/2 ft. long; four hinges; some sheet metal and 2-1/4 yd.
of 8-oz. canvas.

Make a rectangle of the two long pieces and the two 2-ft. 3-in.
pieces of wood as shown in Fig. 2, nailing well the corners
together and reinforcing with a strip of sheet metal as shown in
Fig. 3. The four pieces 1-1/2 ft. long are used for the legs, and
two of them are nailed to one of the pieces 2-1/2 ft. long, making
a support as shown in Fig. 5.

Make two of these--one for each end.

[Illustration: Details of Canvas Cot Construction]

The hinges are attached as shown in Fig. 5 and the whole support
is fastened just under the end pieces of the frame by hinges. Four
pieces of sheet metal are cut as shown in Fig. 4 and fastened to
the body of the frame with their lower ends hooking over pins
driven in each leg at the proper place. The canvas is stretched as
tight as possible over the two long side pieces and fastened on
the outside edge of each piece with large headed tacks. The legs
will fold up as shown by the dotted line and the cot can be stored
in a small space.
--Contributed by R. J. Smith, Milwaukee, Wis.



** How to Make a Small Geissler Tube [154]

At first this would seem to be a difficult piece of work, yet a
good and beautiful Geissler tube can be made at home in the
following manner:

Procure a glass tube about 3-1/2 ft. long having a hole through
its center about 1/8 or 1/4 in. in diameter, about 1 in. of No. 30
platinum wire and enough mercury to fill the tube and a small
bowl. About 1-1/2 lb. of mercury will be sufficient. The first
thing to do is to seal 1/2 in. of platinum wire in one end of the
tube. This is done by holding the end of the tube with the right
hand and taking hold of the tube with the left hand about 4 in.
from the right hand. Hold the tube in a flame of a bunsen burner
in such manner that the flame will strike the tube midway between
the hands, as shown in Fig. 1, and keep turning the tube so as to
get an even heat. When the glass becomes soft,

[Illustration: Construction of Geissler Tube]

remove the tube from the flame and quickly draw it out into a fine
thread. Break this thread off about 1/8 in. from the long part of
the tube and the end will appear as shown in Fig. 2. Take 1/2 in.
of the platinum wire and slip it through the fine hole made by
breaking the glass thread so that one-half of the wire will be
inside of the long tube. If the end of the tube is now placed in
the flame of the burner, the glass will adhere to the platinum
wire and the wire will thus be sealed in the tube. The finished
end will appear as shown in Fig. 3. This tube as described will be
8 in. long, although nearly any size could be made in the same
way.

Measure 8 in. from the sealed end and place the tube at that point
in the flame, holding in the left hand. At the same time take the
piece of glass that was broken off at the end in the first
operation and hold it in the flame with the right hand. When both
the tube and piece of glass are soft, touch the soft part of the
tube with the end of the glass and draw the tube out into a point
like that shown in Fig. 4. Break off the piece of glass, thus
leaving a. small aperture in the long tube. Seal the remaining 1/2
in. of platinum in this aperture in the same manner as before
being careful not to heat the tube too suddenly. The tube is now
ready for filling and the upper part will appear as shown in Fig.
5.

The air is expelled from the tube by filling with mercury. This
may be done by making a paper funnel and pouring the mercury
slowly into the tube through the funnel. When the tube is filled
to within 1/2 in. of the funnel remove the funnel and tap the side
of the tube gently in order to remove any small air bubbles that
may be clinging to the sides of the tube. The air bubbles will
rise and come to the top. The tube now must be filled completely,
expelling all the air. Place a finger over the end of the tube to
keep the mercury in and invert the tube and set the end in the
bowl of mercury. The mercury in the tube will sink until the level
will be at about 30 in., leaving 8 in. of vacuum at the top. The
next operation is to seal the tube at the half-way point between
the lower platinum wire and the mercury level.

As the lower end of the tube must be kept at all times in the bowl
of mercury until the tube is sealed, an assistant will be
necessary for this last operation. Have the assistant hold the
tube in the mercury at a slight angle, using care to always keep
the lower end in the mercury, while you hold the burner in the
left hand and allow the flame to strike the tube at the stated
point. The part of the tube above this point will gradually bend
over of its own weight as the glass softens. When it reaches the
angle of about 60 deg., Fig. 6, take hold of the tube with the
right hand still keeping the flame on the tube, and gradually draw
the softened portion out until it separates from the main tube.

The tube is now finished and when the platinum wires are attached
to the terminals of a spark coil a beautiful blue light will
appear in the tube with a dark space at the negative end or
cathode.
--Contributed by David A. Keys, Toronto, Can.



** Loosening Rusted Nuts [155]

Nuts that are rusted fast can often be loosened by giving a hard
turn in the tightening direction.



** Cleaning Greasy Stoves [155]

Greasy stoves may be cleaned with a strong solution of lye or
soda.



** How to Make a Take-Down Background Frame [156]

Many amateur photographers who desire to do portrait work at home
have left the subject alone for the want of a suitable background.
A frame such as is used by the professional is entirely out of the
question in most homes, says a correspondent of Camera Craft. The
frame as shown in the sketch was devised and its chief advantage
lies in the fact that when not in use it can be compactly tied
together and stored away in a closet.

Almost any wood may be used in constructing this frame, but yellow
pine is the best, as it is easily obtained and at the same time
very well suited for such work. All pieces are to be dressed on
all sides.

Two upright pieces are cut from 3/4 in. material 2 in. wide and 5
ft. 9 in. long and two blocks are fastened on the ends of each
that are to be used for the bottom, as shown in Fig. 1. These
blocks are each 2 by 6-in. and 1/4 in. thick. The base is made
from a piece 3/4 in. thick, 3 in. wide and 5 ft. 4 in. long. A
crosspiece 3/4-in. thick, 3 in. wide and 12 in. long, cut in the
shape shown in Fig. 2, is screwed on each end of the base with
3-in. wood screws, as shown in Fig. 3. Four blocks 1/4 in. thick,
1 in. wide and 3 in. long are nailed to the sides of the base
piece parallel with and at a distance of 2 in. from the end of
same. This forms a slot, Fig. 4, to receive the pieces nailed to
the ends of the uprights. To secure a rigid frame it is essential
that this, joint be accurately put together.

Procure a piece of thick tin or brass and make two pieces like the
pattern shown in Fig. 5, with each projection 3-in. long. The
width of the crosspiece is 1 in. and the single projection 3/4 in.
These are bent and nailed, one on each end of a piece of wood that
is 1/4 in. thick, 1 in. wide and 5 ft. long, as in Fig. 6. These
will form two pockets that will fit over the tops of the uprights.
The frame is put together as shown in Fig. 7. Any background that
will hang straight without need of being stretched can be hung on
this frame.

[Illustration: FIG.6 -- Details of Background Frame]



**  Home-Made Kite Reel [156]

This kite reel is constructed from two old pulleys and a few pipe
fittings. The large pulley is about 14 in. in diameter, on the
face of which are riveted flat strips of iron with extending arms.
These arms are reinforced by riveting smaller pieces from one to
the

[Illustration: Old Pulleys and Pipe Fittings]

other, which connects all arms together on both sides of the
wheel. Mounted on the shaft with the pulleys is a guide for the
kite wire or string. The photograph shows that this guide permits
of being moved entirely over the top of the reel. The smaller
pulley is attached to the shaft and used as a brake. The brake is
used only when running out the wire or string, first removing the
crank.



** Attaching Runners to a Bicycle for Winter Use [157]

Instead of storing away your bicycle for the winter, attach
runners and use it on the ice. The runners can be made from
1/4-in. by 1-in. iron and fastened to the bicycle frame as shown
in the sketch. The tire is removed from the rim of the rear wheel
and large screws turned into the rim, leaving the greater part of
the screw extending. Cut off the heads of the screws and file them
to a point. The rear runners should be set so the rim of the wheel
will be about 1/2 in. above the runner level.
--Contributed by C. R. Welsh, Manhattan, Kan.

[Illustration: Bicycle Fitted with Runners for Snow]



** A Paper That Makes Green Prints [157]

A coating for ordinary paper that is said to give green prints is
made with a two per cent solution of gelatine, says Photography,
and sensitized with the following solution:

    Potassium Bichromate  15 gr.
    Magnesium Sulphate    25 gr.
    Water                  1 oz.

This mixture is spread over the paper in the usual way and the
paper dried in the dark. Printing is carried rather far. The print
is washed, then surface dried or blotted off on a pad and laid
film upwards on a sheet of glass, and the following developer is
applied with a wad of cotton wool wrung out:

    Pyrocatechin  5 gr.
    Water         1 oz.

The picture assumes a rich green color when developed, and is then
washed for five or ten minutes and dried quickly by heat.



** Copies Made from Wax Molds by Electro-Deposition [157]

Fine copies of wax impressions can be made in the following
manner: Procure an ordinary tumbler and fill it with a strong
solution of sulphate of copper, which is made by dissolving two
cents' worth of blue vitriol in 1/2 pt. of water. After this is
done make a porous cell by rolling a piece of brown paper around a
stick and fastening the edge with sealing wax; also, fix a bottom
to the cell in the same way. Make a solution of one part of oil of
vitriol and 5 parts of water and pour this mixture into the porous
cell. Wind the end of a copper wire around the end of a piece of
zinc and place the zinc in the porous cell. Attach the other end
of the wire to the wax impression.

The wax impression is made by pouring melted beeswax on the
article you wish to reproduce and removing after the wax gets
cold. The wax mold then should be coated with black lead and
polished. This is done with a camel's hair brush. A fine copy can
be made on the wax impression after the battery has been running
about 12 hr.
--Contributed by Edward M. Treasdale.

[Illustration: Electro-Deposition]



** How to Make Skating Shoes [158]

Remove the clamp part, as shown in Fig. 1, from an ordinary clamp
skate. Drill holes in the top part of the skate

[Illustration: Skating Shoes]

for screws. Purchase a pair of high shoes with heavy soles and
fasten the skates to the soles with screws, as shown in Fig. 2.
When completed the skating shoes will have the appearance shown on
Fig. 3. These will make as good skating shoes as can be purchased,
and very much cheaper.
--Contributed by Wallace C. Newton, Leominster, Mass.



** How to Make a Self-Setting Rabbit Trap [158]

Secure a good-sized box, say, 1 ft. high, 1-1/2 ft. wide, and 3
ft. long; and to the bottom, about 10 in. from one end, fasten a
2-in. square piece, A, Fig. 1, extending the width of the box.
Place a 10-in. board sloping from the end of the box to the cleat
A. The swing door B, Fig. 1, is made as shown

[Illustration: Self-Setting Trap]

in Fig. 2, which represents the back side of the door. Sheet metal
or tin is cut to the proper size and tacked around the edge of the
hole. This prevents the animal from gnawing its way out, also
provides a way to make the hole of different sizes for squirrels
or other animals. The hole in the door should be about 2 in. wide
and 4 in. high for rabbits. The door is made to swing freely on
two large nails driven through the sides of the box. The hole in
the door being only large enough to admit a small portion of the
rabbit's head, the rabbit will push its way through to the bait,
causing the door to swing back and up, and it will close by its
own weight when the animal is inside. A small door is provided in
the other end to remove the animals caught.

The advantage of this trap is that where one animal is caught
others are liable to follow, and several rabbits will be trapped
at a time. Then, too, the rabbits are not harmed in any way as
they would be if caught in an ordinary trap.
--Contributed by H. F. Church, Alexandria, Va.



** How to Make an Atomizer [158]

Secure a good-sized test tube and fit it with a cork. Take two
glass tubes, with about 1/8-in. hole, and bend them as shown in
the sketch. This is done by heating them at the proper point over
a gas flame until they are soft. Two holes are bored through the
cork and the bent tubes inserted in them, as shown in the sketch,
so that one of the tubes will extend nearly to the bottom

[Illustration: Atomizer]

of the test tube and the other just projecting through the cork.
The spray tube may be made with a fine hole by first securing a
tube longer than necessary and heating it at the proper point and
drawing the tube out into a fine thread. The thread is broken off
at the proper place to make a small hole.



** Home-Made Kits for the Camera [159]

If you have a 5- by 7-in. camera and wish to use some 4- by 5-in.
plates, make a few simple kits to hold the smaller plates and fit
the larger holders, says Camera Craft. Take two pieces of
pasteboard, A and B, black surfaced if possible, and exactly 5 by
7 in. in size. The piece A will form the back of the kit and
should have an opening cut in the center 4 by 5 in. in size. Paste
a piece of strong black paper, C, over the under side of it to
keep the plate from falling through. Cut an opening in the other
piece, B, but cut it 1/4 in. shorter. This opening, being 1/8 in.
shorter at each end, will retain the plate in position and cut off
only that small amount of plate surface when the plate is exposed
in the

[Illustration: Camera Kit]

camera. Cut a piece of thin black cloth, D, 1 in. wide and 5 in.
long. Lay it down on a piece of newspaper and coat one side with
gum or mucilage. Stand the two pieces of 5 by 7 in. black cards on
end together so that they will be square and true and bind the
other ends with the strip of cloth so as to form a hinge. The two
cards form a thickness about equal to a thick glass plate, and go
in the holder in the same way. Lay one of these kits down against
the ground side of the focusing screen and draw a line around,
inside of the opening. This will be a guide as to just what will
be secured upon the smaller plate when the kits are used.



** How to Make a Miniature Stage [159]

A good smooth box, say 8 in. wide, 10 in. high and 12 in. long,
will serve the purpose for the main part of this small theater.
Out two rectangular holes, Fig. 1, one in each end and exactly
opposite each other. Place a screw eye about 1/2 in. from the edge
on each side of these openings. Fit an axle in the screw eyes and
fasten a spool to the middle of the axle. On one of the two spools
attach another smaller spool, Fig. 2, to be used as a driving
pulley. Cut out the front part of the box down to a level with the
top of the spools. Connect the spools with a belt made from tape
about 3/4 in. wide. On this belt fasten figures cut from heavy
paper and made in the form of people, automobiles, trolley cars,
horses and dogs. A painted scenery can be made in behind the
movable tape. The front part of the box may be draped with
curtains, making the appearance of the ordinary stage, as shown in
Fig. 3. A small motor will run the spools and drive the tape on
which the figures are attached.
--Contributed by William M. Crilly, Jr., Chicago.

[Illustration: Details of Stage]



** A Floating Compass Needle [160]

When a thoroughly dry and clean sewing needle is carefully placed
on the surface of water the needle will float even if the density
of steel is 7 or 8 times that of water. A sewing needle thus
floating upon water may be used as a compass, if it has previously
been magnetized. The needle will then point north and south, and
will maintain this position if the containing vessel is moved
about; if the needle is displaced by force it will return to its
position along the magnetic meridian as soon as the restraint is
removed.



** Home-Made Dog Cart [160]

The accompanying photograph shows a boy with his "dogmobile." The
photograph was taken when they were on a new pavement which had 2
in. of sand


Dog-Power Cart

left by the pavers and a grade of 6 per cent. The machine is
nothing more than a boy's rubber-tired wagon on which are mounted
a box for a seat and a wheel steering device extending above and
below the board of the wagon. The front wheels are guided by ropes
attached from each end of the axle and a few turns around the
lower end of the steering rod. A pair of shafts are attached to
the rear, into which the dog is harnessed.



** How to Make a Dry Battery Cell [160]

[Illustration: Dry Battery Cell]

Dry battery cells are composed of the same materials for the
poles, but instead of the liquid commonly used a paste is formed
by mixing sal ammoniac and other salts with water and packed in
the cell so it cannot spill.

A cell of this kind can easily be made, and to make it the proper
size a sheet of zinc 8-1/2 in. long and 6 in. wide will be
required. This zinc is rolled into a cylinder 2-1/2-in. in
diameter. This will allow for a lap of 5/8 in., which is tightly
soldered only on the outside of the seam. Close one end of the
cylinder by soldering a disk of zinc over it, making a watertight
receptacle. All soldering should be done on the outside and none
of the solder allowed to run on the inside of the seam. All seams
on the inside should be painted with asphaltum in order to cover
any particles of solder. Do not paint any surface, only the
joints. Secure three carbon rods 1/2- in. in diameter and 6 in.
long which are copper plated. Carbons used in arc lamps will do.
File the rods to remove the copper plate, leaving about 1/2-in. of
the plate at one end. Tie the three rods in a close bundle with
the copper-plated ends together and make a contact with each rod
by soldering a wire to the plated ends, allowing one end of the
wire to project about 2 in. for a connection. The plated ends of
the carbons should be covered with paraffin for about 1 in. This
is done by immersing them in a dish of smoking hot melted paraffin
until the pores are thoroughly saturated.

The salts for filling are 1/4 lb. zinc oxide, 1 lb. sal ammoniac,
3/4 lb. plaster of paris, 1/4 lb. chloride of zinc mixed into a
paste by adding 1/2 pt. of water. Form a 1/2-in. layer of paste in
the bottom of the cylinder and place the ends of the carbon rods
on this with their plated ends up. Hold the rods in the center of
the cylinder and put the paste in around the rods with a stick.
Pack the paste in, closely filling the cylinder to within 3/4 in.
of the top. This space at the top is filled with a mixture of 1/2
lb. of rosin and 2 oz. beeswax melted together. This wax seals the
cell and prevents any evaporation. Connection is made to the zinc
by soldering a wire to the outside of the cylinder.



** How to Paraffin Wire [161]

The following description of how to make an apparatus with which
to paraffin wire as needed makes clear a method of construction
that is simple and easy to put together in a. short time.

Secure a pan to be used for this purpose only; one that will hold
about 1 qt. The details of the construction are given in the
diagram, in which P is the pan; B is a base of 1 in. pine; S is
the spool of wire supported near one end of the base by nailing on
standards H and H; F is a spool, with narrow flanges, supported
near the bottom of the pan by the standards T and T. These may be
made of two short pieces of a roller fitted into the holes bored
in the base; A is a block of l-in. pine with a piece of leather
tacked on one side. Four nails should be driven in the base just
outside of the edge of the pan to keep it from sliding off the
pan.

Bore a hole in the base between the two spools and pass the wire
through this hole, under the spool in the paraffin, then through a
small hole in the leather and a notch in the block A, and a notch
between the base and the pan. Tie a string around the wire between
the leather and the paraffin, making the knots so they will not
pull through the hole in the leather. This makes the wire smooth,
and by making the string tighter or looser you can regulate the
thickness of the paraffin, says Electrician and Mechanic. Place
the pan on the stove; when the paraffin is melted, pull out the
wire as needed. To keep the pan from sliding place a flatiron or
some other weight on it.

[Illustration: Home-Made Apparatus for Paraffining Wire]



** Uses of Peat [161]

Peat is used in Germany for bedding, fodder, filter, fuel and
packing purposes.



** Scientific Explanation of a Toy [162]

In a recent Issue of Popular Mechanics an article on "The Turning
Card Puzzle" was described and illustrated. Outside of the
scientific side involved herein I describe a much better trick.
About the time when the expression "skidoo" first began to be used
I invented the following trick and called it "Skidoo" and
"Skidee," which created much merriment. Unless the trick is
thoroughly understood, for some it will turn one way, for others
the opposite way, while for others it will not revolve at all. One
person whom I now recall became red in the face by shouting skidoo
and skidee at it, but the thing would not move at all, and he
finally, from vexation, threw the trick into the fire and a new
one had to be made. Very few can make it turn both ways at will,
and therein is the trick.

Take a piece of hardwood 3/8-in. square and about 9 in. long. On
one of the edges cut a series of notches as indicated in Fig 1.
Then slightly taper the end marked B until it is nicely rounded as
shown in Fig. 2. Next make an arm of a two-arm windmill such as
boys make. Make a hole through the center of this one arm. Enlarge
the hole slightly, enough to allow a common pin to hold the arm to
the end B and not interfere with the revolving arm. Two or three
of these arms may have to be made before one is secured that is of
the exact proportions to catch the vibrations right.

[Illustration: How to Cut the Notches]

To operate the trick, grip the stick firmly in one hand, and with
the forward and backward motion of the other allow the first
finger to slide along the top edge, the second finger along the
side and the thumb nail will then vibrate along the notches, thus
making the arm revolve in one direction. To make the arm revolve
in the opposite direction--keep the hand moving all the time, so
the observer will not detect the change which the band
makes--allow the first finger to slide along the top, as in the
other movement, the thumb and second finger changing places: e.
g., in the first movement you scratch the notches with the thumb
nail while the hand is going from the body, and in the second
movement you scratch the notches with the nail of the second
finger when the hand is coming toward the body, thus producing two
different vibrations. In order to make it work perfectly (?) you
must of course say "skidoo" when you begin the first movement, and
then, no matter how fast the little arm is revolving when changed
to the second movement, you must say "skidee" and the arm will
immediately stop and begin revolving in the opposite direction. By
using the magic words the little arm will obey your commands
instantly and your audience will be mystified. If any of your
audience presume to dispute, or think they can do the same, let
them try it. You will no doubt be accused of blowing or drawing in
your breath, and many other things in order to make the arm
operate. At least it is amusing. Try it and see.
--Contributed by Charles Clement Bradley, Toledo, Ohio.

*     *    *    *    *    *    *

The foregoing article describing the "Skidoo-Skidee Trick"
appeared in a recent issue of Popular Mechanics. I have been told
that a similar arrangement is used by a tribe of Indians in the
state of Washington, by the Hindoos in India, and one friend tells
me that they were sold on the streets of our large cities many
years ago.

This toy interested me so much that I have made an investigation
into the causes of its action, and I think the results may be of
interest.

To operate, one end of the notched stick is held firmly in the
left hand, while with the right hand a nail or match stick is
rubbed along the notched edge, at the same time pressing with the
thumb or finger of the moving hand against the oblique face of the
stick. The direction of rotation depends upon which face is
pressed. A square stick with notches on edge is best, but the
section may be circular or even irregular in shape. The
experiments were as follows:

1. A rectangular stick had notches cut on one face. When the
pressure was applied upon a face normal to the first, no rotation
resulted. If the pressure was upon an edge, rotation was obtained.

2. Irregular spacing of the notches did not interfere with the
action. The depth of the notches was also unimportant, although it
should be suited to the size of the nail for best results.

3. The hole in the revolving piece must be larger than the pin; if
there is a close fit no rotation is obtained.

4. The center of gravity of the revolving piece must lie within
the hole. If the hole is not well centered the trick cannot be
performed.

5. If the stick be clamped in a vise no results are obtained; with
this exception: if the stick has enough spring, and the end
clamped is far enough away from the notched portion, the rotation
may be obtained.

The above experiments led me to the conclusion that the operation
of the device is dependent upon a circular motion of the pin, and
this was confirmed by the following experiments. The action is
somewhat similar to swinging the toy known as a locust around with
a slight circular motion of the hand, It is necessary to show here
that a slight circular motion is sufficient to produce the result
and, secondly, that such motion can be produced by the given
movements of the hands.

6. A piece of brass rod was clamped in the chuck of a lathe, and a
depression made in the end slightly eccentric, by means of a
center punch. If the end of the pin is inserted in this
depression,

[Illustration: The Lathe Experiment]

while the hand holding the other end of the stick is kept as
nearly as possible in the axis of the lathe, rotation of the lathe
will produce rotation of the revolving piece. Speeds between 700
and 1,100 r. p. m. gave the best results.

7. A tiny mirror was attached to the end of the pin, and the hand
held in the sunlight so that a spot of sunlight was reflected upon
the wall. The notches were then rubbed in the usual way. The spot
of light upon the wall moved in a way which disclosed two
components of motion, one circular and one due to the irregular
movements of the hand holding the stick. Usually the orbit was too
irregular to show a continuous and closed circular path, but at
times the circular motion became very pronounced. It was observed
and the direction of rotation correctly stated by a man who was
unaware of the source of the motion. The production of the
circular motion can be explained in this way:

When the rubbing nail comes to a notch the release of pressure
sends the stick upward; this upward motion against the oblique
pressure upon the (say) right hand side gives also a lateral
component of motion towards the left. As the nail strikes the
opposite side of the notch the stick is knocked down again, this
motion relieves somewhat the oblique pressure from the right hand
side, and, the reaction from the holding (left) hand moves the
stick to the right slightly, so that it is back in the old
position for the next upward motion. Thus a circular or elliptic
motion is repeated for each notch, and the direction of this
motion is the same whether the nail be rubbed forward or back. For
oblique side pressure from the right (notches assumed upward), the
motion of the stick and hence of the revolving piece will be
counter-clockwise; if the pressure is from the left, it will be
clockwise.

That the motion of the revolving piece is due to a swinging
action, and not to friction of the pin in the hole, is proved by
experiments 3 and 4.
--Contributed by M. G. Lloyd, Ph.D., Washington, D. C.



** Home-Made Lantern [163]

[Illustration: Tin Can Lantern]

The accompanying picture shows a lantern which can be made almost
anywhere for immediate use. All that is needed is an empty tomato
or coffee can, a piece of wire and a candle. Make a hole a little
smaller than the diameter of a candle and about one-third of the
way from the closed end of the can, as shown. A wire is tied
around the can, forming a handle for carrying. This kind of
lantern can be carried against almost any wind and the light will
not be blown out.
--Contributed by G. A. Sloan, Duluth, Minn.



** A Study of Splashes [164]

When a rough, or greasy, or dusty sphere falls into a liquid, the
liquid is

[Illustration: Splashes from a Sphere In Milk and Water]

forced away from the sphere. If the sphere is quite smooth the
liquid rises up around and enclosing it in a sheath says Knowledge
and Scientific News.

Reproduced herewith are a series of photographs showing successive
stages in the entry of a rough sphere into milk and water, and the
resultant "basket splash." The diameter of this sphere was about
3/5 in., and the height of the fall about 6 in. Examination of the
photographs shows that the liquid, instead of flowing over and
wetting the surface of the sphere, is driven violently away, so
far as can be seen from the photographs, the upper portion is, at
first, unwetted by the liquid. The gradual thickening of the
crater wall and the corresponding reduction in the number of its
lobes as the subsidence proceeds is beautifully shown. Thereafter
there rises from the depth of the crater an exquisite jet which in
obedience to the law of segmentation at once splits up in its
upper portion into little drops, while at the same time it gathers
volume from below and rises ultimately as a tall, graceful column
to a height which may be even greater than that from which the
sphere fell.



** How to Make a Stick Pin [164]

A fine stick pin or button can be made from a new one-cent piece.
Carefully file out all the metal around the Indian head and
slightly round the edges. Solder a pin to the back of the head
when it is to be used for a stick pin. If a collar button base is
soldered to the back of the head instead of the pin it can be used
for a button. These can be gold plated by a jeweler and then you
will have a neat pin or button, or a good emblem for the Order of
Redmen.

[Illustration: Stick Pin]



** How to Make a Miniature Electric Locomotive [165]

A miniature electric railway is a thing that attracts the
attention of almost any person. The cost of a toy electric
locomotive is beyond the reach of many boys who could just as well
make such a toy without much expense and be proud to say they
"built it themselves." The electric locomotive described herewith
uses for its power a small battery motor costing about $1. The
first thing to do is to make the wheels and axles. If one has no

[Illustration: The Different Parts for Making the Electric
Locomotive]

lathe, the wheels can be turned at some machine shop. Four wheels
are made from a round bar of metal, as shown in Fig. 1. Each wheel
is 1/4 in. thick and 1 in. in diameter, with a 1/16-in. flange and
a 1/4-in. hole drilled in the center. Each pair of wheels is
fitted on a 1/4-in. axle, about 2-5/8 in. long. One of the axles
should be fitted with a grooved belt wheel, as shown. Make the
frame from three pieces of heavy brass, as shown in Fig. 2.

The first piece, or main part of the frame, is made from brass,
3/4 in. wide and 16 in. long, bent into an oblong shape and the
ends soldered or bolted together. If the ends are to be soldered,
before doing so drill four 1/4-in. holes 1 in. from the ends and
insert the ends of the axles. The other two pieces are 1/2-in.
wide and of the dimensions shown in the sketch. These pieces are
riveted in the middle of the oblong frame, each in its proper
place. The motor is now bolted, bottom side up, to the top of the
piece fastened to the frame lengthwise. A trolley, Fig. 3, is made
from a piece of clock spring, bent as shown, and a small piece of
tin soldered to the top end for a brush connection. A groove is
made in the tin to keep the trolley wire in place.

The trolley wire is fastened to supports made of wood and of the
dimensions given in Fig. 4. The trolley should be well insulated
from the frame. The parts, put together complete, are shown in
Fig. 5. Run a belt from the pulley on the motor to the grooved
wheel on the axle, as shown in Fig. 6, and the locomotive is ready
for running.

In making the connections the travel of the locomotive may be made
more complicated by placing a rheostat and controlling switches in
the line, so that the engine can be started and stopped at will
from a distance and the speed regulated. Automatic switches can be
attached at the ends of the line to break the circuit when the
locomotive passes a certain point.

One connection from the batteries is made to the trolley wire and
the other to a rail. The connection for the motor runs from one
binding post to the trolley and this connection must be well
insulated to avoid a short-circuit. The other binding-post is
connected to the frame.

The cost of making the wheels and purchasing the track will not be
over $1.50. The track can be made from strips of tin put in a saw
cut made in pieces of wood used for ties. This will save buying a
track.
--Contributed by Maurice E. Fuller, San Antonio, Texas.



** Demagnetizing a Watch [166]

A test can be made to know if your watch is magnetized by placing
a small compass on the side of the watch nearest the escapement
wheel if the compass pointer moves with the escapement wheel the
watch is magnetized. A magnetized watch must be placed in a

[Illustration: Watch Demagnetizer]

coil that has an alternating current of electricity flowing
through it to remove the magnetism. A demagnetizer can be made as
shown in the illustration. Two end pieces for the coil are made as
shown in Fig. 1 from 1/4-in. wood. These ends are fastened
together, Fig. 2, with cardboard 3 in. long glued to the inside
edges of the holes cut in them. Wind upon the spool thus formed
about 2 lb. of No. 16 cotton-covered copper wire. As it will be
necessary to place a 16-cp. lamp in series with the coil, both the
coil and lamp can be mounted on a suitable base and connected as
shown in Fig. 3. The current, which must be 110 volt alternating
current, is turned on the lamp and coil and the magnetized watch
slowly drawn through the opening in the center of the coil.
--Contributed by Arthur Liebenberg, Cincinnati, O.



** How to Make a Pocket Skate Sharpener [166]

Secure a square file and break off a piece, Fig 1, the length of a
paper clip, Fig. 2. Draw the temper in the ends of this piece of
file, but do not heat the center. This can be done by wrapping a
wet piece of cloth or asbestos around the middle and holding it in
the jaws of a pair of tongs which will only leave the end
uncovered and projecting from the tongs about 1/2 in. Hold this
projecting end in a flame of a plumber's torch until it is a dull
red. Allow this to cool slowly while in the tongs. When cold treat
the other end in the same way. This will draw the temper in only
the ends which are filed, as shown in Fig. 1, and holes drilled in
them. Also drill a hole in each end of the spring on the paper
clip to match those drilled in the piece of file. Fasten the file
in the clip with small bolts, as shown in Fig. 3. When the file
gets filled with filings it can be removed and cleaned. Place the
runner of the skate in the clip and hold flat on the surface of
the runner. If the piece of file is fitted to the same width as
the skate runner the sides of the paper clip will hold the file
level with the surface of the runner without any trouble. Push the
clip back and forth until the skate is sharpened.

[Illustration: Sharpener for Skates]



** Old-Time Magic [167]



** Trick with a Coin in a Wine Glass [167]

The accompanying sketch shows a. trick of removing a dime from the
bottom of an old fashioned wine glass without touching the coin.
The dime is first placed in the bottom of the glass and then a
silver quarter dropped in on top. The quarter will not go all the
way down. Blow hard into the glass in the position shown and the
dime will fly out and strike the blower on the nose.

[Illustration: Coin Trick]



** Untying-a-Knot Trick [167]

Tie a double knot in a silk handkerchief, as shown in the
accompanying sketch and tighten the last tie a little by slightly
drawing the two upper ends; then continue to tighten much more,
pulling vigorously at the first corner of the handkerchief, and as
this end belongs to the same corner it cannot be pulled much
without loosening the twisted line of the knot to become a
straight line. The other corner forms a slip knot on the end,
which can be drawn out without disturbing the form, or apparent
security of the knot, at the moment when you cover the knot with
the unused part of the handkerchief. When the trick is to be
performed, tie two or three very hard knots that are tightly drawn
and show your audience that they are not easy to untie. The slip
knot as described then must be made in apparently the same way

[Illustration: Knot Trick]

and untied with the thumb while the knot is in the folds of the
handkerchief.



** Gear-Cutting Attachment for Small Lathes [167]

When in need of small gears for experimental or model machines the
amateur usually purchases them, never thinking that he could make
them on his own lathe. A small attachment can be made to fasten in
the tool post of a lathe and the attachment made to take a mandrel
on which to place the blank for cutting a gear. The frame is made
from a 1/2 in. square iron bent as shown in the sketch with the

[Illustration: Gear-Cutting Attachment for Lathes]

projecting end filed to fit the tool post of the lathe. A pair of
centers are fitted, one of which should have a screw thread and
lock nut for adjustment in putting in and removing the mandrel.

All the old clock wheels that can be found should be saved and
used for index wheels. All of these wheels should be fitted to one
end of the mandrel. The blank wheel is put on the outer end of the
mandrel and a clock wheel having the number of teeth desired
placed on the other end. When the mandrel is put in between the
centers a small pawl is fastened with a screw to the frame with
its upper end engaging in a tooth of the clock wheel. One clock
wheel will index more than one number of teeth on a blank wheel.
For instance: if the clock wheel has 18 teeth it can be made to
index 6, 9 or 18 teeth to the blank by moving the number of teeth
each time 3, 2 and 1 respectively. In the sketch, A shows the end
of the cutter and B the side and the shape of the cutting tool.
When the cutter A, which is in a mandrel placed in the centers of
the lathe, has finished a cut for a tooth, the pawl is disengaged
and the mandrel turned to another tooth in the clock wheel.

In order to get the desired height it is sometimes necessary to
block up the lathe head and the final depth of the tooth adjusted
by the two screws in the projecting end of the frame which rests
on the rocker in the tool post. Should too much spring occur when
cutting iron gears the frame can be made rigid by blocking up the
space between it and the lathe bed.

The cutter mandrel is placed in the centers of the lathe, or
should the lathe head be raised, a short mandrel with the cutter
near the end can be placed in a chuck, and adjusted to run true.
The frame holding the mandrel, gear blank and clock wheel is
inserted in the tool post of the lathe and adjusted for depth of
the cutter. The lathe is started and the gear blank fed on the
cutter slowly until the tooth is cut. The pawl is released and the
mandrel turned to the proper number of teeth and the operation
repeated. In this manner gears 3 in. in diameter can be made on a
6-in. swing lathe.
--Contributed by Samuel C. Bunker, Brooklyn, N.Y.



** Wire Terminals for Battery Connections [168]

[Illustration: Cotter Pin Wire Terminal]

Good connections on the end of wires for batteries can be made
from cotter pins, Fig. 1, about 1-1/2 in. long. Each end of the
wire is put through the eye of a cotter pin, twisted around itself
and soldered. The connection and eye are then covered with tape as
shown in Fig. 2. When connecting to batteries, spread the pin and
push the parts under the nut with one part on each side of the
binding-post. When the nuts are tightened the connection will be
better than with the bare wire.
--Contributed by Howard S. Bott.



** Simple Arts and Crafts Leather Work [168]

Very interesting and useful pieces of leather work can be done
with nothing more for equipment than a cup pointed nail set such
as carpenter use, and a nut pick.

The accompanying illustrations show some of the things that can be
made. Beginning at the left and reading to the right they are:
Case for court-plaster, coin purse, lady's card case, eye glass
cleaner or pen wiper (has chamois skin within). Second row: Two
book marks, note book, blotter back, book mark. Third row: Pin
ball (has saddler's felt between the two leather disks), tea
cosey, gentleman's card case or bill book. Fourth row: Needle or
pin case, tea cosey, lady's belt bag, watch fob ready for
fastenings.

Procure a piece of Russian calf modeling leather. (1.) Make on
paper the design wanted. (2.) Moisten the back side of the leather
with sponge or cloth with as much water as it will take yet not
show through on the face side. (3.) Place the leather on some hard
non-absorbent material, such as brass or marble. (4.) Place the
paper design on the leather and, holding it in place with the left
hand, trace the outline, of the object and the decorative design
with the nut pick so as to make a V-shaped groove in the leather.
(5.) Take the paper off and working on the leather directly make
the grooves deeper. (6.) With the cup-pointed nail set stamp the
background promiscuously. This is done by making an effort to hold
the point of the set about 1/4 in. above the surface, at the same
time striking light, rapid blows on the top with a hammer or
mallet.

[Illustration: This Work Is Done with a Nail Set and Nut Pick]

With such objects as coin purses and card cases, a sewing machine
will be needed to fasten the parts together. An ordinary machine
will do. Frequently the parts are fastened by punching holes and
lacing through these with leather thongs or silk cord.

In making symmetrical designs such as are here shown, draw center
lines across the required space, dividing it into as many parts as
desired. Make free-hand one quarter of the design, if four parts
are to be alike, or one-half of the design, if but two parts. Fold
over along these center lines. Put a piece of double-surfaced
carbon paper between the parts and trace over the design already
drawn.



** How to Make a Simple Still [170]

A still to distill water can be made from a test tube, some heavy
rubber hose, and an ordinary bottle. Secure

[Illustration: Distilling Water]

a stopper for the test tube, and bore a hole through the center,
into which fit a small piece of tube. The bottle is also fitted
with a stopper containing a piece of tube, and both bottle and
test tube connected with a rubber tube.

The test tube is partly filled with water and supported or held
over an alcohol lamp. The bottle should stand in a basin of cold
water. When the water in the test tube begins to boil the steam
passes over to the bottle, where it condenses. The basin should be
supplied with cold water as fast as it begins to get warm. The
rubber tube will not stand the heat very long and if the still is
to be used several times, a metal tube should be supplied to
connect the test tube and bottle.



** Homemade Mariner's Compass [170]

Magnetize an ordinary knitting needle, A, and push it through a
cork, B, and place the cork exactly in the middle of the needle.
Thrust a pin, C, through the cork at right angles to the needle
and stick two sharpened matches in the sides of the cork so that
they will project downward as shown. The whole arrangement is
balanced on a thimble with balls of wax stuck on the heads of the
matches. If the needle is not horizontal, pull it through the cork
to one side or the other, or change

[Illustration: Magnetized Needle Revolving on a Pin]

the wax balls. The whole device is placed in a glass berry dish
and covered with a pane of glass.



** Brighten White Paint [170]

Add aluminum bronze to a white or light paint that is to be used
for lettering on a dark ground.



** Quartz Electrodes Used in Receiving Wireless Messages [170]

[Illustration: Details of the Receiving Instrument]

Wireless messages have been received at Washington, D.C., from Key
West, Florida, a distance of 900 miles, through a receiving
instrument in which two pieces of quartz of different composition
were used on the electrodes. In making an instrument of this kind
the quartz can be purchased from a dealer in minerals. One piece
must contain copper pyrites and the other zincites. The electrodes
are made cupping to hold the minerals and each should have a screw
adjustment to press the pieces of quartz in contact with each
other. Connect as shown in the illustration, using a high
resistance receiver.
--Contributed by Edwin L. Powell, Washington, D. C.



** How to Make a Glider [171]
By Carl Bates

A gliding machine is a motorless aeroplane, or flying-machine,
propelled by gravity and designed to carry a passenger through the
air from a high point to a lower point some distance away. Flying
in a glider is simply coasting down hill on the air, and is the
most interesting and exciting sport imaginable. The style of
glider described in this article is known as the "two-surface" or
"double-decked" aeroplane, and is composed of two arched cloth
surfaces placed one above the other.

In building a glider the wood material used should be
straight-grained spruce, free from knots. First prepare from
spruce planks the following strips of wood. Four long beams 3/4
in. thick, 1-1/4 in. wide and 20 ft. long; 12 crosspieces 3/4 in.
thick, 3/4 in. wide and 3 ft. long; 12 uprights 1/2 in. thick,
1-1/2 in. wide and 4 ft long; 41 strips for the bent ribs 3/16 in.
thick, 1/2-in. wide and 4 ft. long; 2 arm sticks 1 in. thick, 2
in. wide and 3 ft. long; the rudder sticks 3/4 in. square and 8 ft
long; several strips 1/2 in. by 3/4 in. for building the vertical
and horizontal rudders. The frames for the two main surfaces
should be constructed first, by bolting the crosspieces to the
long beams at the places shown by the dimensions in Fig. 1. If
20-ft. lumber cannot be procured, use 10-ft. lengths and splice
them, as shown in Fig. 3. All bolts used should be 1/8 in. in
diameter and fitted with washers on both ends. These frames formed
by the crosspieces should be braced by diagonal wires as shown.
All wiring is done with No. 16 piano wire.

The 41 ribs may be nailed to the main frames on the upper side by
using fine flat-headed brads 7/8 in. long. These ribs are spaced 1
ft. apart and extend 1 ft. beyond the rear edges of the main
frames, as shown in Fig. 1. After nailing one end of a rib to the
front long beam, the rib is arched by springing down the loose end
and nailing to the rear beam. The ribs should have a curve as
shown in Fig. 2, the amount of curvature being the same in all the
ribs.

The frames of the main surfaces are now ready to be covered with
cloth. Cambric or bleached muslin should be used for the covering,
which is tacked to the front edge, stretched tightly over the bent
ribs and fastened securely with tacks to the rear ends of the
ribs. The cloth should also be glued to the ribs for safety. In
the center of the lower plane surface there should be an opening 2
ft. wide and 4 ft. long for the body of the operator. Place the
two main surfaces 4 ft. apart and connect with the 12 uprights,
placed in the corner of each crosspiece and beam. The uprights are
fastened by bolting to the crosspieces, as shown in Fig. 2. The
whole structure is made strong and rigid by bracing with diagonal
wires, both laterally and longitudinally.

The vertical rudder is to keep the machine headed into the wind
and is not movable. This rudder is made of cloth stretched over a
light wooden frame, which is nailed to the rudder sticks
connecting to the main frame. The horizontal rudder is also made
of cloth stretched over a light wooden frame, and arranged to
intersect the vertical rudder at its center. This rudder is held
in position and strengthened by diagonal wires and guy wires. The
horizontal rudder is also immovable and its function is to prevent
the machine from diving, and also to keep it steady in its flight.
The rudders are fastened to the glider by the two rudder sticks,
and these sticks are held rigid by diagonal wire and also by guy
wires leading to the sides of the main frames as shown in Fig. 1.
The two arm sticks should be spaced about 13 in. apart and bolted
to the long beams in the center of the opening in the lower plane
where the operator is to take his position.

The glider should be examined to see

[Illustration: Details of the Glider]

that the frame is not warped or twisted. The surfaces must be true
or the machine will be hard to balance when in flight. To make a
glide, take the glider to the top of a hill, get in between the
arm sticks and lift the machine up until the arm sticks are under
the arms as shown run a few steps against the wind and leap from
the ground. You will find that the machine has a surprising amount
of lift, and if the weight of the body is in the right place you
will go shooting down the hillside in free flight. The landing is
made by pushing the weight of the body backwards. This will cause
the glider to tip up in front, slacken speed and settle. The
operator can then land safely and gently on his feet. Of course,
the beginner should learn by taking short jumps, gradually
increasing the distance as he gains skill and experience in
balancing and landing.

The proper position of the body is slightly ahead of the center of
the planes, but this must be found by experience. The machine
should not be used in winds blowing faster than 15 miles an hour.
Glides are always made against the wind, and the balancing is done
by moving the legs. The higher the starting point the farther one
may fly. Great care should be exercised in making landings;
otherwise the operator might suffer a sprained ankle or perhaps a
broken limb. The illustration shows two lines of flight from a
hilltop, the glider travels on the upper line caused by the body
of the operator taking a position a little back of the proper
place, and on the lower line he changes his position from front to
back while flying, which causes the dip in the line.



** Boys Representing the Centaur [173]

This is a diversion in which two boys personate a Centaur, a
creature of Greek mythology, half man and half horse. One of the
players stands erect and the other behind him in a stooping
position with his hands upon the first player's hips, as shown in
Fig. 1. The

[Illustration: Making Up the Centaur]

second player is covered over with a. shawl or table cover which
is pinned around the waist of the first player. A tail made of
strips of cloth or paper is pinned to the rear end of the cover.
The first player should hold a bow and arrow and have a cloak
thrown loosely over his shoulder as shown in Fig. 2. Imitation
hoofs of pasteboard may be made and fastened over the shoes.



** Home-Made Ladle for Melting Babbitt [173]

Secure a large sized old bicycle bell and rivet a heavy wire or
strap iron on one side for a handle. When heated a little, hammer
out the edge on one side for a lip to pour from. This makes a good
ladle for melting small amounts of babbit or lead. --Contributed
by L. M. Olson, Bellingham, Wash



** How to Make a Flash Lamp [174]

Indoor photographs are made much better with the use of a
flashlight than by depending on light from windows. The lighting
can be made from any direction to suit the operator. If lighting
flash powder when not in a regular flash lamp the flash cannot be
depended upon and in some instances is dangerous. To make a simple
and inexpensive flash lamp, first secure from your druggist an
empty salve box about 3 in. in diameter. While at the drug store
get 3 ft. of small rubber tubing; this will cost about 15 cents.
Now visit the tin shop and get a small piece of scrap tin 3 or 4
in. square; a piece of brass or steel wire, about the size of
stove pipe wire, 14 in. long. These with a strip of light asbestos
paper and some small iron wire, about the size of door screen
wire, will complete the material list.

Carefully punch a hole through the salve box on one side near the
bottom with a 10-penny nail. Cut a strip of tin 2 in. long and
about 3/8 in. wide and roll this around a 8-penny nail so as to
form a small tube which will just fit the hole made in the salve
box. Next roll up a strip of tin 1/2 in. wide into a small cup
about 3/8 in. in diameter at one end and 1/4 in. at the other.

Place the tube in the nail hole so that one end comes almost to
the center of the box inside and the other end projects about 1/2
in. outside the box. Cut out a little place for the tube to enter
the cup at the small end and then solder the tube and cup to the
bottom of the box as shown in the illustration. The tube and cup
should be well soldered on the seams to make them airtight. Bend a
ring on one end of the larger piece of wire, making it 2-1/2 in.
in diameter and form the remaining portion of the wire into a
spiral, soldering the end in the bottom of the box near the cup.
Wrap the ring at the top of the spiral piece of wire all the way

[Illustration: Made from a Tin Salve Box ]

around with the strip of asbestos paper, wrapping them together
over and over until the entire ring is covered. Slip the end of
the rubber tube over the tin tube on the side of the box and the
flash lamp is complete.

To make a flash with this lamp fill the little cup in the center
with flash powder and moisten the asbestos ring with alcohol. When
all is ready for the picture the alcohol is lighted and a quick
blow of the breath through the rubber tube will force the flash
powder upward into the flame and cause the flash.

When through with the lamp place the cover over it, pushing the
asbestos ring down inside the box. Wind the rubber tubing around
the box and you have a neat outfit that can be carried in the
pocket.



** Photographing the New Moon [174]

To make a photograph of the moon is quite difficult and no good
picture can be made without an expensive apparatus. At home and
with your own hand camera you can make a good picture of the new
moon by the use of a flash light on a tennis ball, the tennis ball
taking the part of the moon. The ball is suspended in front of a
black cloth screen, the camera focused by holding a burning match
near the ball and the exposure made by burning a

[Illustration: Tennis Ball Photographed]

small quantity of flash powder at one side and a little below the
ball. The light from the flash only striking one side of the ball
gives the effect of the new moon. --Photo by M. M. Hunting,
Dayton, O.



** Old-Time Magic- Part II [175]



** Removing Scissors from a Cord [175]

A piece of strong cord is doubled and fastened to a pair of
scissors with a slip knot, as shown in Fig. 1. After passing the
ends of the cord through the thumb hole of the scissors they are
tied fast to a chair, door knob or any other object that may be of
sufficient size to make the ends secure. The trick is to release
the scissors without cutting the cord.

Take hold of the loop end of the cord in the lower handle and
drawing it first

[Illustration: How the Scissors Are Removed]

through the upper handle and then completely over the blades of
the scissors, as shown in Fig. 2. This is very simple when you
know how, but puzzling when the trick is first seen.



** Coin and Card on the First Finger [175]

This is a simple trick that many can do at the first attempt,
while others will fail time after time. It is a good trick to
spring upon a company casually if you have practiced it
beforehand. A playing card is balanced on the tip of the
forefinger and a penny placed on top immediately over the finger
end, as shown in the sketch. With the right hand forefinger and
thumb strike the edge of the card sharply. If done properly the
card will flyaway, leaving the penny poised on the finger end.

[Illustration: Coin and Card]



** How to Make Sealing Wax Hat Pins [175]

Select a stick of sealing wax of the desired color for the
foundation of the hat pin. Hold the end of the stick over a flame
until the wax is soft enough to drop; then put it on the hat-pin
head. When sufficient wax has adhered to the pin, hold the lump
over the flame, revolving the pin at the same time so the wax will
not drop and the head will form a round ball. The head can be made
in any shape desired while warm. When the desired shape has been
obtained, cool thoroughly in cold water and dry carefully.

Stripes and designs may be put on the foundation by applying drops
of other brilliant colored wax, and by careful manipulation the
wax when warm can be made to flow around the pin head and form
pretty stripes and designs. If a certain color is to be more
prominent, the wax to make this color must be applied last and the
pin put through the flame again. Cool in water and dry, as before,
and pass once more through the flame to obtain the luster.



** Old-Time Magic-Part III [176]



** Disappearing Coin [176]

While this is purely a sleight-of-hand trick, it will take very
little practice to cause the coin to disappear instantly. Take a
quarter of a dollar between the thumb and finger, as shown, and by
a rapid twist of the fingers whirl the coin and at the same time
close the hand, and the coin will disappear up your coat sleeve.
On opening the hand the coin will not be seen. Take three quarters
and hold one in the palm of the left hand, place the other two,
one between the thumb and finger of each hand, then give the coin
in the right hand a whirl, as described, closing both hands
quickly. The coin in the right hand will disappear up your sleeve,
and the left hand on being unclosed will contain two quarters,
while the one in the right shall have disappeared.

[Illustration: Disappearing Coin]



** Sticking a Coin Against the Wall [176]

Cut a small notch in a coin--ten cent piece or quarter will do--so
a small point will project. When this is pressed firmly against a
wood casing or partition the coin will stick tightly.



** A Chinese Outdoor Game [176]

The accompanying illustration shows the "grand whirl," or the
Chinese students' favorite game. This game is played by five
persons, four of them turning around the fifth or central figure

[Illustration: Chinese Doing the Grand Whirl]

with their arms locked about each other and the two outside
persons swinging in midair with their bodies almost horizontal.



** Home-Made Photograph of a Lightning Flash [176]

How many times has each amateur photographer tried to photograph
the lightning's flash? Some good pictures have been obtained by a
ceaseless effort on the part of the operator. Here is a method by
which you can make a picture of a streak of lightning on a clear
night in your own house. Paste two strips of black paper on a
piece of glass that is 10 in. square so as to leave a clear space
through the center 2-in. or more in width. Smoke this uncovered
space over a candle's flame until the soot is thick enough to
prevent light passing through. Take a sharp lead pencil and
outline a flash of lightning upon the smoked surface, using a fine
needle to make the smaller lines, and then set the glass up
against the back of two boxes which are set to have a space
between them of 4 or 5 in.

A lighted candle is held behind the glass so the light will shine
through for focusing the camera. After darkening the room set your
camera ready for the exposure and burn a small quantity of flash
light powder in the same place in which the candle was held. This
will make an impression upon the plate of the flash drawn on the
smoked glass.

[Illustration: Lightning Flash]



** How to Make a Static Machine [177]

Static electricity is produced by revolving glass plates upon
which a number of sectors are cemented; these sectors, passing
through neutralizing brushes, distribute electric charges

[Illustration: Details of a Homemade Static Machine]

to collecting combs attached to discharging rods. The glass
selected for the plates must be clear white glass, free from
wrinkles, and of a uniform thickness. Two plates are necessary to
make this machine, and the glass should be of sufficient size to
cut a circular plate 16-in. in diameter. A hole must be made
exactly in the center of each plate, and this should be done
before cutting the circle. One of the best ways to make the hole
is to drill the glass with a very hard-tempered drill, the cutting
edge of which should be kept moistened with 2 parts turpentine and
1 part sweet oil while drilling. The hole is to be made 3/4 in. in
diameter. The circle is then marked on each plate and cut with a
glass cutter. The plates are trued up, after they are mounted, by
holding a piece of emery wheel to the edges while they are
turning. Water should be applied to the edges while doing the
work.

The sectors are cut from tinfoil, 1-1/2 in. wide at one end, 3/4
in. at the other, and 4 in. long. A thin coat of shellac varnish
is applied to both sides of the plates, and 16 sectors put on one
side of each plate, as shown in Fig. 1. The divisions can be
marked on the opposite side of the plate and a circle drawn as a
guide to place the sectors at proper intervals.

The sectors should lie flat on the glass with all parts smoothed
out so that they will not be torn from their places as the plates
revolve. The shellac should be tacky when the pieces of tinfoil
are put in place.

The collectors are made, as shown in Fig. 2, from about 1/4-in.
copper wire with two brass balls soldered to the ends. The fork
part is 6 in. long and the shank 4 in. Holes are drilled on the
inside of the forks, and pins inserted and soldered. These pins,
or teeth, should be long enough to be very close to the sectors
and yet not scratch them when the plates are turning.

The frame of the machine is made from any kind of finished wood
with dimensions shown in Fig. 3, the side pieces being 24 in. long
and the standards 3 in. wide. The two pieces, C C, Fig. 3, are
made from solid, close grained wood turned in the shape shown,
with the face that rests against the plate 4 in. in diameter, and
the outer end 1-1/2 in. in diameter, the smaller end being turned
with a groove for a round belt. Before turning the pieces a hole
is bored through each piece for the center, and this hole must be
of such a size as to take a brass tube that has an internal
diameter of 3/4 in. The turned pieces are glued to the glass
plates over the center holes and on the same side on which the
sectors are fastened. Several hours' time will be required for the
glue to set. A fiber washer is then put between the plates and a
brass tube axle placed through the hole. The plates, turned wood
pieces, and brass axle turn on a stationary axle, D.

The drive wheels, EE, are made from 7/8-in. material 7 in. in
diameter, and are fastened on a round axle cut from a broom
handle. This wood axle is centrally bored to admit a metal rod
tightly, and extends through the standards with a crank attached
to one end.

Two solid glass rods, GG, Fig. 4, 1 in. in diameter and 15 in.
long, are fitted in holes bored into the end pieces of the frame.
Two pieces of 1-in. brass tubing and the discharging rods, RR, are
soldered into two hollow brass balls 2 or 2-1/2 in. in diameter.
The shanks of the collectors are fitted in these brass balls with
the ends extending, to which insulating handles are attached.
Brass balls are soldered to the upper ends of the discharging
rods, one having a 2-in. ball and the other one 3/4 in. in
diameter.

Caps made from brass are fitted tightly on the ends of the
stationary shaft, D, and drilled through their diameter to admit
heavy copper rods, KK, which are bent as shown. Tinsel or fine
wire such as contained in flexible electric wire are soldered to
the ends of these rods, and the brushes thus made must be adjusted
so they will just touch the plates. The caps are fitted with
screws for adjusting the brushes. These rods and brushes are
called the neutralizers. A little experimenting will enable one to
properly locate the position of the neutralizers for best results.
--Contributed by C. Lloyd Enos, Colorado City, Colo.



** A Concrete Swimming Pool [178]

[Illustration: Home-Made Swimming Pool]

Several boys from a neighborhood in the suburbs of a large city
concluded to make for themselves a swimming tank of concrete. The
money was raised by various means to purchase the cement, and the
work was done by themselves. The ground was selected in a secluded
spot in a neighbor's back yard and a hole dug to a depth of 4 ft.,
12 ft. wide and 22 ft. long. The concrete was made by mixing 1
part cement, 4 parts sand and 10 parts gravel together and the
bulk moistened with water. The bottom was made the same as laying
a sidewalk, and forms were only used for the inside of the
surrounding wall. The tank may be hidden with shrubbery or vines
planted to grow over a poultry wire fence.



** Old-Time Magic-Part IV [179]

Cutting a Thread Inside of a Glass Bottle [179]

This is a trick which can only be performed when the sun shines,
but it

[Illustration: The Glass Directs the Sun's Rays]

is a good one. Procure a clear glass bottle and stick a pin in the
lower end of the cork. Attach a thread to the pin and tie a small
weight to the end of the thread so it will hang inside the bottle
when the cork is in place. Inform your audience that you will
sever the thread and cause the weight to drop without removing the
cork.

All that is required to perform the feat is to hold a magnifying
glass so as to direct the sun's rays on the thread. The thread
will quickly burn and the weight fall.



** Removing a Key from a Double String [179]

Tie the ends of a 5-ft. string together, making a double line on
which a key is placed and the string held as shown by the dotted
lines in the sketch. Turn the palms of the hands toward you and
reach over with the little finger of the right hand and take hold
of the inside line near the left-hand thumb.

[Illustration: "The Key Will Drop from the String"]

Reverse the operation and take hold of the inside line near
right-hand thumb with the little finger of the left hand. You will
then have the string as it appears in the sketch. Quickly let
loose of the string with a little finger on one hand and a thumb
on the other and pull the string taut. The key will drop from the
string.



** How to Bore a Square Hole [179]

You would not consider it possible to bore a square hole in a
piece of cardboard, yet such a thing can be done. Take a cardboard
or a thin piece of wood, fold and place it between two pieces of
board with the fold up; the boards are then put in a vise as
shown. Start the bit with the screw point in the fold, using a
1-in. bit, and bore a

[Illustration: Boring a Square Hole]

hole 1/2 in. deep. When the cardboard is taken from the vise it
will appear as shown at B and when unfolded, as at A.



** HOW TO MAKE COPPER TRAYS [180]

Copper trays such as are shown in the accompanying illustration
are very useful as well as ornamental about the house. They can be
used to keep pins and needles, pens and pencils, or cigar ashes,
etc. They are easily made, require no equipment in the way of
tools except what are usually found about the house, unless it
would be the metal shears, and when the decorations are well
designed and the metal nicely colored, they make attractive little
pieces to have about.

The first thing to do in preparation for making them is to prepare
the design. Simple designs work out better than fussy ones and are
more likely to be within the ability of the amateur. Having
determined the size of the tray, draw on paper an oblong to
represent it. Inside this oblong, draw another one to represent
the lines along which the metal is to be bent up to form the
sides. Inside this there should be drawn still another oblong to
represent the margin up to which the background is to be worked.
The trays shown are 5-3/4 by 6-3/4 in., the small ash tray 4 by 4
in., the long pen and pencil tray 4-3/4 by 9-1/2 in. The second
oblong was 3/4 in. inside the first on all, and the third one 1/4
in. inside the second on all.

If the decoration is to have two parts alike--symmetrical--divide
the space with a line down the middle. Draw one-half the design
free hand, then fold along this line and trace the second half
from this one. If the lines have been drawn with soft pencil,
rubbing the back of the paper with a knife handle will force
enough of the lead to the second side so that the outline can be
determined. Four-part symmetry will require two lines and two
foldings, etc.

For the metal working there will be needed a pair of tin shears,
two spikes, file, flat and round-nosed pliers, screw-driver and
sheet copper of No. 23 gauge. Proceed as follows: 1. Cut off a
piece of copper so that it shall have 1/2 in. extra metal on each
of the four sides. 2. With a piece of carbon paper trace upon the
copper lines that

[Illustration: Articles Made from Copper]

shall represent the margin of the tray proper and the lines along
which the upturned sides of the tray are to be bent; also trace
the decorative design. 3. With a nail make a series of holes in
the extra margin, about 3/4-in. apart and large enough to take in
a 3/4-in. slim screw. 4. Fasten the metal to a thick board by
inserting screws in these holes. 5. With a 20-penny wire nail that
has the sharpness of its point filed off, stamp the background
promiscuously. By holding the nail about 1/4 in. above the work
and striking it with the hammer, at the same time striving to keep
it at 1/4 in. above the metal, very rapid progress can be made.
This stamping lowers the background and at the same time raises
the design. 6. Chase or stamp along the border of the design and
background, using a nail filed to chisel edge. This is to make a
clean, sharp division between background and design. 7. When the
stamping is completed, remove the screws and the metal from the
board and cut off the extra margin with the metal shears. File the
edges until they are smooth to the touch. 8. With the flat pliers
"raise" one side of the tray, then the other side. 9. Raise the
ends, adjusting the corners as shown in the illustration. Use the
round-nosed pliers for this purpose.

Copper is frequently treated chemically to give it color. Very
pretty effects may be obtained by covering the tray with
turpentine, then moving it about over a flame such as a bunsen
burner until the turpentine burns off. The copper will "take on"
almost all the colors of a rainbow, and the effect will be most
pleasing.



** Photograph of a Clown Face [181]

At first glance the accompanying photograph will appear as if the
person photographed is wearing a false face or has his face
painted like a clown. On close observation you will notice that
the face is made on the bald head of the person sitting behind the
table. The eyes, nose and mouth are cut from black paper and
pasted on the bald spot. The subject's face is horizontal and
resting upon his hands.

[Illustration: A Bald Head Photographed]



** Finger Mathematics [181]
By Charles C. Bradley

All machinists use mathematics. Ask a machinist what would be the
product of 9 times 8 and his ready reply would be 72, but change
the figures a little and say 49 times 48 and the chances are that
instead of replying at once he will have to figure it out with a
pencil. By using the following method it is just as easy to tell
at a glance what 99 times 99 are as 9 times 9. You will be able to
multiply far beyond your most sanguine expectations.

In the first numbering, begin by holding your hands with the palms
toward the body and make imaginary numbers on the thumbs and
fingers as follows: Thumbs, 6; first fingers, 7; second fingers,
8; third fingers, 9, and fourth fingers, 10. Suppose you desire to
multiply 8 by 9, put the eighth finger on one hand against the
ninth finger of the other hand as shown.

[Illustration: "8 Times 9"]

The two joined fingers and all the fingers above them (calling the
thumbs fingers) are called the upper fingers and each has a value
of ten, which tens are added. All the fingers below the joined
fingers are termed the lower fingers, and each of the lower
fingers represents a unit value of one. The sum of the units on
one hand should be multiplied by the sum of the units on the other
hand. The total tens added to this last named sum will give the
product desired. Thus: Referring to above picture or to your hands
we find three tens on the left hand and four tens on the right,
which would be 70. We also find two units on the left hand and one
on the right. Two times one are two, and 70 plus 2 equals 72, or
the product of 8 times 9.

Supposing 6 times 6 were the figures. Put your thumbs together;
there are no fingers above, so the two thumbs represent two tens
or 20; below the thumbs are four units on each hand, which would
be 16, and 20 plus 16 equals 36, or the product of 6 times 6.

[Illustration: "6 Times 6"   "10 Times 7"]

Supposing 10 times 7 is desired. Put the little finger of the left
hand against the first finger of the right hand. At a glance you
see seven tens or 70. On the right hand you have three units and
on the left nothing. Three times nothing gives you nothing and 70
plus nothing is 70.

In the second numbering, or numbers above 10, renumber your
fingers; thumbs, 11; first fingers, 12, etc. Let us multiply 12 by
12.

Put together the tips of the fingers labeled 12. At a glance you
see four tens or 40. At this point we leave the method explained
in Case 1 and ignore the units (lower fingers) altogether. We go
back to the upper fingers again

[Illustration: "12 Times 12"]

and multiply the number of upper fingers used on the one hand by
the number of upper fingers used on the other hand, viz., 2 times
2 equals 4. Adding 4 to 40 gives us 44. We now add 100 (because
anything over 10 times 10 would make over 100) and we have 144,
the product of 12 times 12.

The addition of 100 is arbitrary, but being simple it saves time
and trouble. Still, if we wish, we might regard the four upper
fingers in the above example as four twenties, or 80, and the six
lower fingers as six tens, or 60; then returning to the upper
fingers and multiplying the two on the right hand by the two on
the left we would have 4; hence 80 plus 60 plus 4 equals 144;
therefore the rule of adding the lump sum is much the quicker and
easier method.

Above 10 times 10 the lump sum to add is 100; above 15 times 15 it
is 200; above 20 times 20, 400; 25 times 25, 600, etc., etc., as
high as you want to go.

In the third numbering to multiply above 15 renumber your fingers,
beginning the thumbs with 16, first finger 17, and so on. Oppose
the proper finger tips as before, the upper fingers representing a
value of 20. Proceed as in the first numbering and add 200. Take
For example 18 times 18.

At a glance we see six twenties plus 2 units on left hand times 2
units on right hand plus 200 equals 324.

In the fourth numbering the fingers are marked, thumbs, 21, first
fingers 22, etc., the value of the upper fingers being 20. Proceed
as in the second lumbering, adding 400 instead of 100.

[Illustration: "18 Times 18"]

Above 25 times 25 the upper fingers represent a value of 30 each
and after proceeding as in the third numbering you add 600 instead
of 200.

This system can be carried as high as you want to go, but you must
remember that for figures ending in 1, 2, 3, 4 and 5 proceed as in
the second numbering. For figures ending in 6, 7, 8, 9 and 10 the
third numbering applies.

Determine the value of the upper fingers whether they represent
tens, twenties, thirties, forties, or what. For example, any two
figures between 45 and 55, the value of the upper fingers would be
50, which is the half-way point between the two fives. In 82 times
84 the value of the upper fingers would be 80 (the half-way point
between the two fives, 75 and 85, being 80). And the lump sum to
add.

Just three things to remember:

Which numbering is to follow, whether the one described in second
or third numbering; the value which the upper fingers have; and,
lastly, the lump sum to add, and you will be able to multiply
faster and more accurately than you ever dreamed of before.



** Optical Illusions [183]

If a person observes fixedly for some time two balls hanging on
the end of cords which are in rapid revolution, not rotation,
about a vertical axis, the direction of revolution will seem to
reverse. In some experiments two incandescent "pills" of platinum
sponge, such as an used for lighting gas-burners, were hung in
tiny aluminum bells from a mica vane wheel which was turned
constantly and rapidly in one direction by hot air from a gas
flame to keep the platinum in a glow. The inversion and reversion
did not take place, as one might suppose, at the will of the
observer, but was compulsory and followed regular rules. If the
observer watches the rotating objects from the side, or from above
or from below, the inversion takes place against his will; the
condition being that the image on the retina shall be eccentric.
It takes place also, however, with a change in the convergence of
the optical axes, whether they are parallel to each other or more
convergent. Also when the image on the retina is made less
distinct by the use of a convex or concave lens, the revolution
seems to reverse; further, in the case of a nearsighted person,
when he removes his spectacles,

[Illustration: Illusions Shown by Revolving Platinum Sponge
"Pills" and Hat Pins]

inversion results every time that the image on the retina is not
sharp. But even a change in the degree of indistinctness causes
inversion.

The cause of this optical illusion is the same where the wings of
windmills are observed in the twilight as a silhouette. It is then
not a question of which is the front or the back of the wheel, but
whether one of the wings or the other comes towards the observer.
The experiment is made more simple by taking a hat pin with a
conspicuous head, holding it firmly in a horizontal position, and
putting a cork on the point. Looking at it in semi-darkness, one
seems to see sometimes the head of the pin, sometimes the point
towards him, when he knows which direction is right. The inversion
will be continued as soon as one observes fixedly a point at the
side. Here it is a question of the perception of depth or
distance; and this is the same in the case of the rotating balls;
the direction of seeming revolution depends on which one of them
one considers to be the front one and which the rear one.

From the foregoing the following conclusion may be reached: When,
in the case of a perception remitting two appearances, one fixedly
observes one of these and then permits or causes change in the
sharpness of the image on the retina, the other appearance asserts
itself.



** Steam Engine Made from Gas Pipe and Fittings [184]

Almost all the material used in the construction' of the parts for
the small steam engine illustrated herewith was made from gas pipe
and fittings. The cylinder consists of a 3-in. tee, the third
opening being threaded and filled with a cast-iron plug turned to
such a depth that when the interior was bored out on a lathe the
bottom of the plug bored to the same radius as the other part of
the tee. The outside end of the plug extended about 1/4-in. and
the surface was made smooth for the valve seat. A flat slide valve
was used.

The ports were not easy to make, as

[Illustration: The Engine Is About 20 Inches High]

they had to be drilled and chipped out. The steam chest is round,
as it had to be made to fit the round tee connection. The
crosshead runs in guides made from a piece of gas pipe with the
sides cut out and threads cut on both ends. One end is screwed
into a rim turned on the cylinder head and the other is fitted
into an oblong plate. Both ends of this plate were drilled and
tapped to receive 1-1/2-in. pipe.

The main frame consists of one 1-1/2in. pipe 10 in. long and one
made up from two pieces of pipe and a cross to make the whole
length 10 in. These pipes were then screwed into pipe flanges that
served as a base. The open part of the cross was babbitted to
receive the main shaft. The end of the shaft has a pillow block to
take a part of the strain from the main bearing. The eccentric is
constructed of washers. While this engine does not give much
power, it is easily built, inexpensive, and anyone with a little
mechanical ability can make one by closely following out the
construction as shown in the illustration.
--Contributed by W. H. Kutscher, Springfield, Ill.



** How to Make a Copper Bowl [185]

To make a copper bowl, such as is shown in the illustration,
secure a piece of No. 21 gauge sheet copper of a size sufficient
to make a circular disk 6-1/2 in. in diameter.

Cut the copper to the circular form and size just mentioned, and
file the edge so that it will be smooth and free from sharp
places. With a pencil compass put on a series of concentric rings
about 1/2 in. apart. These are to aid the eye in beating the bowl
to form.

The tools are simple and can be made easily. First make a
round-nosed mallet of some hard wood, which should have a diameter
of about 1-1/4 in, across the head. If nothing better is at hand,
saw off a section of a broom handle, round one end and insert a
handle into a hole bored in its middle. Next take a block of wood,
about 3 by 3 by 6 in., and make in one end a hollow, about 2 in.
across and 1/2 in. deep. Fasten the block solidly, as in a vise,
and while holding the copper on the hollowed end of the block,
beat with the mallet along the concentric rings.

Begin at the center and work along the rings--giving the copper a
circular movement as the beating proceeds--out toward the rim.
Continue the circular movement and work from the rim back toward
the center. This operation is to be continued until the bowl has
the shape desired, when the bottom is flattened by placing the
bowl, bottom side up, on a flat surface and beating the raised
part flat. Beating copper tends to harden it and, if continued too
long without proper treatment, will cause the metal to break. To
overcome this hardness, heat the copper over a bed of coals or a
Bunsen burner to a good heat. This process is called annealing, as
it softens the metal.

The appearance of a bowl is greatly enhanced by the addition of a
border. In the illustration the border design shown was laid out
in pencil, a small hole was drilled with a band drill in each
space and a small-bladed metal saw inserted and the part sawed
out.

To produce color effects on copper, cover the copper with
turpentine and

[Illustration: Shaping the Bowl and Sawing the Lace]

hold over a Bunsen burner until all parts are well heated.



** Cleaning Furniture [185]

After cleaning furniture, the greasy appearance may be removed by
adding some good, sharp vinegar to the furniture polish. Vinegar,
which is nothing else than diluted acetic acid, is one of the best
cleansers of dirty furniture.



** Melting Lead in Tissue Paper [185]

Take a buckshot, wrap it tightly in one thickness of tissue paper,
and, holding the ends of the paper in the fingers of each hand,
place the part that holds the shot over the flame of a match just
far enough away from the flame not to burn the paper. In a few
seconds unfold the paper and you will find that the shot has
melted without even scorching the paper.
--Contributed by W. O. Hay, Camden, S. C.



** The Principles of the Stereograph [185]

Each of our eyes sees a different picture of any object; the one
sees a trifle more to the right-hand side, the other to the left,
especially when the object is near to the observer. The
stereoscope is the instrument which effects this result by
bringing the two pictures together in the senses. The stereograph
produces this result in another way than by prisms as in the
stereoscope. In the first place there is

[Illustration: Looking Through the Colored Gelatine]

only one picture, not two mounted side by side. The stereograph
consists of a piece of card, having therein two circular openings
about 1-1/4 in. diameter, at a distance apart corresponding to the
distance between the centers of the pupils. The openings are
covered with transparent gelatine, the one for the left eye being
blue, that for the right, orange. The picture is viewed at a
distance of about 7 in. from the stereograph. As a result of
looking at it through the stereograph, one sees a colorless black
and white picture which stands out from the background. Try
looking at the front cover of Popular Mechanics through these
colored gelatine openings and the effect will be produced.

If one looks at the picture first with the right eye alone through
the orange glass, and then with the left eye through the blue
glass, one will understand the principle on which the little
instrument works. Looking through the blue glass with the left
eye, one sees only those portions which are red on the picture.
But they seem black. The reason is that the red rays are absorbed
by the blue filter. Through the orange gelatine all the white
portions of the picture seem orange, because of the rays coming
from them, and which contain all the colors of the spectrum; only
the orange rays may pass through. The red portions of the picture
are not seen, because, although they pass through the screen, they
are not seen against the red ground of the picture. It is just as
though they were not there. The left eye therefore sees a black
picture on a red background.

In the same way the right eye sees through the orange screen only
a black picture on a red background; this black image consisting
only of the blue portions of the picture. Any other part of
complementary colors than blue and orange, as for instance red and
green, would serve the same purpose.

The principle on which the stereograph works may be demonstrated
by a very simple experiment. On white paper one makes a picture or
mark with a red pencil. Looking at this through a green glass it
appears black on a green ground; looking at it through a red glass
of exactly the same color as the picture, it, however, disappears
fully.

Through the glass one will see only a regular surface of the color
of the glass itself, and without any picture. Through a red glass
a green picture will appear black.

So with the stereograph; each eye sees a black picture
representing one of the pictures given by the stereoscope; the
only difference being that in the case of the stereograph the
background for each eye is colored; while both eyes together see a
white background.

In the pictures the red and the green lines and dots must not
coincide; neither can they be very far apart in order to produce
the desired result. In order that the picture shall be "plastic,"
which increases the sense of depth and shows the effect of
distance in the picture, they must be a very trifle apart. The
arrangement of the two pictures can be so that one sees the
pictures either in front of or on the back of the card on which
they are printed. In order to make them appear before the card,
the left eye sees through a blue screen, but the red picture which
is seen by it is a black one, and lies to the right on the
picture; and the right eye sees the lefthand picture. The further
apart the pictures are, the further from the card will the
composite image appear.

In the manufacture of a stereoscope the difficulty is in the
proper arrangement of the prisms; with the stereograph, in the
proper choice of colors.



** Mercury Make-and-Break Connections for    Induction Coils [187]

Induction coils operating on low voltage have a make-and-break
connection called the "buzzer" to increase the secondary
discharge. Two types of make-and-break connection are used, the
common "buzzer" operated by the magnetism of the core in the coil
and the mercury break operated by a small motor. The sketch
herewith shows how to make the motor-operated break. Two blocks of
wood are nailed together in the shape of an L and a small motor
fastened to the top of the vertical piece. The shaft of the motor
is bent about 18 in. in the shape of a crank, so that in turning
it will describe a circle 1/4 in. in diameter. A small connecting
bar is cut from a piece of brass 1/8 in. thick, 1/4 in. wide and 1
in. long and a hole drilled in each end; one hole to fit the motor
shaft and the other to slip on a No. 12 gauge wire. Two L-shaped
pieces of brass are fastened to the side of the block and drilled
with holes of such a size that a No. 12 gauge wire will slip
through snugly. Place a NO.12 gauge wire in these holes and bend
the top end at right angles.

[Illustration: Motor-Driven Make-and-Break]

Put the connecting brass bar on the motor shaft with washers
fitted tight on each side and slip the other end over the bent end
of the wire. Have the wire plenty long so it can be cut to the
proper length when the parts are all in place. A small round
bottle about 1/2 in. in diameter is now fitted in a hole that has
been previously bored into the middle of the bottom block and
close up to the vertical piece. This should only be bored about
half way through the block. The wire is now cut so at the length
of the stroke the end will come to about one-half the depth, or
the middle of the bottle.

Fill the bottle with mercury to a point so that when the motor is
running, the end of the wire will be in the mercury for about
one-half of the stroke. Cover the mercury over with a little
alcohol. A No. 14 gauge iron wire is bent and put into the side of
the bottle with the end extending to the bottom. The other end of
this wire is attached to one binding-post placed at the end of the
bottom block. The other binding-post is connected to a small brass
brush attached to the side of the vertical piece, which is placed
with some pressure on the moving wire. The motor can be run with a
current from a separate course or connected as shown on the same
batteries with the coil. The proper height of the mercury can be
regulated for best results. The motor must run continuous if the
coil is used for writing code signals, wireless, etc.
--Contributed by Haraden Pratt, San Francisco, Cal.



** How to Make a Barometer [188]

Atmospheric pressure is measured by the barometer. The weight of
the air in round numbers is 15 lb. to the square inch and will
support a column of water 1 in. square, 34 ft. high, or a column
of mercury (density 13.6) 1 in. square, 30 in. high. The parts
necessary to make a simple barometer are, a glass tube 1/8 in.
internal diameter and about 34 in. long, a bottle 1 in. inside
diameter and 2 in. high. Seal one end of the tube by holding it in
the flame of a gas burner, which will soon soften the glass so it
can be pinched together with pliers. Put a little paraffin in the
bottle and melt it by holding the bottle over a small flame. When
cool the paraffin should cover the bottom about 1/16 in. thick.
The tube is now to be filled with mercury. This may be
accomplished with a paper funnel, but before attempting to put in
the mercury, place a large dish or tray beneath the tube to catch
any mercury that may accidentally be spilled. Only redistilled
mercury should be used, and the tube should be perfectly clean
before filling. When the tube is filled to

[Illustration: Barometer]

within 1 in. of the open end place the forefinger over the hole
and tilt the tube up and down so all the air will gather at the
finger end. The filling is continued until the tube is full of
mercury. The glass bottle containing the wax covered bottom is now
placed over the end of the tube and pressed firmly to insure an
airtight fit with the tube. The bottle and tube are inverted and
after a few ounces of mercury are put in the bottle the tube may
be raised out of the wax, but be careful not to bring its edge
above the surface of the mercury.

The instrument is put aside while the base is being made, or, if
you choose, have the base ready to receive the parts just
described when they are completed. Cut a base from a piece of
7/8-in. pine 3 in. wide and 40 in. long. In this base cut a groove
to fit the tube and the space to be occupied by the bottle is
hollowed out with a chisel to a depth of 3/4 in., so the bottle
rests on one-half of its diameter above the surface of the board
and one-half below. The instrument is made secure to the base with
brass strips tacked on as shown in the sketch. After the
instrument is in place put enough mercury in the bottle so the
depth of the mercury above the bottom end of the tube will be
about 1/2 in.

The scale is made on a piece or cardboard 2 in. wide and 4 in.
long. The 4 in. are marked off and divided into sixteenths, and
the inches numbered 27 up to 31. The scale is fastened to the base
with glue or tacks and in the position behind the tube as shown in
the sketch. Before fastening the scale, the instrument should be
compared with a standard barometer and the scale adjusted so both
readings are the same. But if a standard barometer is not
available, the instrument, if accurately constructed, will
calibrate itself.

In general, a drop in the mercury indicates a storm and bad
weather, while a rise indicates fair weather and in winter a
frost. Sudden changes in the barometer are followed by like
changes in weather. The slow rise of the mercury predicts fair
weather, and a slow fall, the contrary. During the frosty days the
drop of the mercury is followed by a thaw and a rise indicates
snow.



** Home-Made Post or Swinging Light [189]

Remove the bottom from a round bottle of sufficient size to admit
a wax or tallow candle. This can be done with a glass cutter or a
hot ring; the size of the outside of the bottle, which is slipped
quickly over the end. Procure a metal can cover, a cover from a
baking powder can will do, a lid fit it on the end where the
bottom was removed. The cover is punched full of holes to admit
the air and a cross cut in the center with the four wings thus
made by the cutting turned up to form a place to insert the
candle. The metal cover is fastened to the bottle with wires as
shown in the sketch. This light can be used on a post or hung from
a metal support.

[Illustration: Swinging Light]



** A Checker Puzzle [189]

Cut a block from a board about 3 in. wide and 10 in. long.
Sandpaper all the surfaces and round the edges slightly. Mark out
seven 1-in. squares on the surface to be used for the top and
color the squares alternately white and black. Make six men by
sawing a curtain roller into pieces about 3/8 in. thick. Number
the pieces 1, 2, 3, 5, 6 and 7, and place them as shown in Fig. 1.
The puzzle is to make the first three change places with the last
three and

[Illustration: Position of the Men]

move only one at a time. This may be done as follows:

    Move 1-Move No. 3 to the center.
    Move 2-Jump No. 5 over No. 3.
    Move 3-Move No. 6 to No. 5's place.
    Move 4-Jump No, 3 over No. 6.
    Move 5-Jump No. 2 over No. 5.
    Move 6-Move No. 1 to No. 2's place.
    Move 7-Jump No. 5 over No. 1.
    Move 8-Jump No. 6 over No. 2.
    Move 9-Jump No. 7 over No. 3.
    Move 10-Move No. 3 into No. 7's place.
    Move ll-Jump No. 2 over No. 7.
    Move 12-Jump No, l over No. 6.
    Move 13-Move No. 6 into No. 2's place.
    Move 14-Jump No. 7 over No. 1.
    Move 15-Move No. 1 into No, 5's place.

After the 15 moves are made the men will have changed places. This
can be done on a checker board, as shown in Fig. 2, using checkers
for men, but be sure you so situate the men that they will occupy
a row containing only 7 spaces.
--Contributed by W. L. Woolson, Cape May Point, N.J.



** Gold Railroad Signals [189]

Covering railroad signals with gold leaf has taken the place of
painting on some roads. Gold leaf will stand the wear of the
weather for 15 or 20 years, while paint requires recovering three
or four times a year.



** How to Make a Bell Tent [190]

A bell tent is easily made and is nice for lawns, as well as for a
boy's camping outfit. The illustrations show a plan of a tent
14-ft. in diameter. To make such a tent, procure unbleached tent
duck, which is the very best material for the purpose, says the
Cleveland Plain Dealer. Make 22 sections, shaped like Fig. 3, each
10 ft. 6 in. long and 2 ft. 2 in. wide at the bottom, tapering in
a straight line to a point at the top. These dimensions allow for
the laid or lapped seams, which should be

[Illustration: An Inexpensive Home-Made Tent]

double-stitched on a machine. The last seam sew only for a
distance of 4 ft. from the top, leaving the rest for an opening.
At the end of this seam stitch on an extra gusset piece so that it
will not rip. Fold back the edges of the opening and the bottom
edge of the bell-shaped cover and bind it with wide webbing, 3 in.
across and having eyelets at the seams for attaching the stay
ropes. Near the apex of the cover cut three triangular holes 8 in.
long and 4 in. wide at the bottom and hem the edges. These are
ventilators. Make the tent wall of the same kind of cloth 2 ft. 2
in. high. Bind it at the upper edge with webbing and at the bottom
with canvas. Also stitch on coarse canvas 6 in. wide at the
bottom, and the space between the ground and the wall when the
tent is raised, fill with canvas edging. Stitch the upper edge of
the wall firmly to the bell cover at the point indicated by the
dotted line, Fig. 2.

For the top of the tent have the blacksmith make a hoop of 1/4-in.
round galvanized iron, 6-in. diameter. Stitch the canvas at the
apex around the hoop and along the sides. Make the apex into a
hood and line it with stiff canvas. Have the tent pole 3 in. in
diameter, made in two sections, with a socket joint and rounded at
the top to fit into the apex of the tent.

In raising the tent, fasten down the wall by means of loops of
stout line fastened to its lower edge and small pegs driven
through them into the ground, Fig. 5. Run the stay ropes from the
eyelets in the circular cover to stakes (Fig. 5) stuck in the
ground. Use blocks, as in Fig. 6, on the stay ropes for holding
the ends and adjusting the length of the ropes.



** Simple X-Ray Experiment [190]

The outlines of the bones of the hand may be seen by holding a
piece of rice paper before the eyes and placing the spare hand
about 12 in. back of the rice paper and before a bright light. The
bony structure will be clearly distinguishable.
--Contributed by G.J. Tress, Emsworth, Pa.



** How to Make a Candle Shade [191]

Layout the pattern for the shade on a thin piece of paper, 9 by 12
in., making the arcs of the circle with a pencil compass. As shown
in the sketch, the pattern for this particular shade covers a half
circle with 2-3/4 in. added. Allowance must be made for the lap
and as 1/4 in. will do, a line is drawn parallel 1/4 in. from the
one drawn through the center to the outside circle that terminates
the design.

Nail a thin sheet of brass, about 9 in. wide by 12 in. long, to a
smooth board of soft wood, then trace the design on the brass by
laying a piece of carbon paper between the pattern and the brass.
After transferring the design to the brass, use a small awl to
punch the holes in the brass along the outlines of the figures
traced. Punch holes in the brass in the spaces around the outlined
figures, excepting the 1/4-in. around the outside of the pattern.
When all the holes are punched, remove the brass sheet from the
board and cut it along the outer lines as traced from the pattern,
then bend the brass carefully so as not to crease the figures
appearing in relief. When the edges are brought together by
bending, fasten them with brass-headed nails or brads.

If a wood-turning lathe is at hand, the shade can be made better
by turning a cone from soft wood that will fit the sheet-brass
shade after it is shaped and the edges fastened together. The
pattern is traced as before, but before punching the holes, cut
out the brass on the outside lines, bend into shape, fasten the
ends together and place on the wood cone. The holes are now
punched on the outlines traced from the pattern and the open
spaces made full of holes. The holes being punched after the shade
is shaped, the metal will stay and hold the perfect shape of a
cone much better.

The glass-beaded fringe is attached on the inside of the bottom
part with small brass rivets or brads placed about 3/4 in. apart.
The thin sheet brass may be procured from the local hardware

[Illustration: Punching the Holes; Completed Shade; Pattern]

dealer and sometimes can be purchased from general merchandise
stores.
--Contributed by Miss Kathryn E. Corr, Chicago.



** A Putty Grinder [191]

Having a large number of windows to putty each week, I found it
quite a task to prepare the putty. I facilitated the work by using
an ordinary meat cutter or sausage grinder. The grinder will
soften set putty and will quickly prepare cold putty. It will not,
however, grind old putty or make putty from whiting and oil.
--Contributed by H. G. Stevens; Dunham, Que.



** Home-Made Small Churn [192]

Many people living in a small town or in the suburbs of a city own
one

[Illustration: Making Butter]

cow that supplies the family table with milk and cream. Sometimes
the cream will accumulate, but not in sufficient quantities to be
made into butter in a large churn. A fruit jar usually takes the
place of a churn and the work is exceedingly hard, the jar being
shaken so the cream will beat against the ends in the process of
butter-making. The accompanying sketch shows clearly how one boy
rigged up a device having a driving wheel which is turned with a
crank, and a driven wheel attached to an axle having a crank on
the inner end. This crank is connected to a swinging cradle with a
wire pitman of such a size as to slightly bend or spring at each
end of the stroke. The cradle is made with a cleat fastened to
each end, between which is placed the fruit jar, partially filled
with cream. The jar is wedged in between the cleats and the
churning effected by turning the crank.
--Contributed by Geo. E. Badger, Mayger, Oregon.



** Home-Made Round Swing [192]

Gas pipe and fittings were used wherever possible in the making of
the swing as shown in the photograph. The d i a g ram drawing
shows the construction. A 6-in. square cedar post is set in the
ground about 3 ft., allowing 2 ft. to remain above the ground and
a 7/8-in. piece of shafting is driven into the top part of this
post for an axle. A cast-iron ring, or, better still, a heavy
wheel with four spokes of such a size as to be drilled and tapped
for 1/2-in. pipe is used for the hub, or center on which the frame
swings. If a wheel is selected, the rim must be removed and only
the spokes and hub used. The hole in the hub must be 7/8 in. or
less, so the hub can be fitted to the shafting that is driven in
the post. A large washer is placed on top of the post and the hub
or cast-iron ring set on the washer.

The drilled and tapped holes in the four spokes are each fitted
with a 4-1/2 length of 1/2-in. pipe. These pipes are

[Illustration: The Merry-Go-Round Complete]

each fitted with a tee on the end and into this tee uprights of
1/2-in. pipe in suitable lengths are screwed, and also short
lengths with a tee and axle for the 6-in. wheel are fitted in the
under side of the tee. The uprights at their upper ends are also
fitted with tees and each joined to the center pipe with 1/2-in.
pipe flattened on the inner end and fastened with bolts to a
flange.

The bottom part of the cloth covering is held in place by a
1/2-in. pipe, bent to the desired circle. Four braces made from
1/2-in. pipe connect each spoke and seat to the flange on the
center pipe. An extra wheel 18 in. in diameter is fitted in
between two seats and used as the propelling wheel. This wheel has
bicycle cranks and pedals and carries a seat or a hobby horse. The
four seats are fastened to the four pipes with 1/2-in. pipe
clamps.

[Illustration: Details of the Swing]

Small miniature electric lights are fastened to the overhead
braces and supplied with electric current carried through wires to
the swing by an ingenious device attached to the under side of the
cast-iron ring or hub of the wheel. A ring of fiber on which two
brass rings are attached is fastened to the hub and connections
are made to the two rings through two brushes fastened to the post
with a bracket. The wires run under the surface of the ground
outside and connected to the source of electricity. The wires from
the brass rings run through the center pipe to the top and are
connected to the lamp sockets.



** Old-Time Magic-Part V [193]



** The Disappearing Coin [193]

This is an uncommon trick, entirely home-made and yet the results
are as startling as in many of the professional tricks. A small
baking-powder can is employed to vanish the coin, which should be
marked by one of the audience for identification. Cut a slot in
the bottom on the side of the can, as shown in Fig. 1. This slot
should be just large enough for the coin that is used to pass
through freely, and to have its lower edge on a level with the
bottom of the can.

The nest or series of boxes in which the coin is afterwards found
should consist of four small sized flat pasteboard boxes square or
rectangular shaped and furnished with hinged covers. The smallest
need be no larger than necessary to hold the coin and each
succeeding box should be just large enough to hold the next
smaller one which in turn contains the others.

A strip of tin about 1 by 1-3/4 in. is bent in the shape as shown
in Fig. 2 to serve as a guide for the coin through the various
boxes. This guide is inserted about 1/8 in. in the smallest box
between the cover and the box and three rubber bands wrapped
around the box as indicated. This box is then enclosed in the next
larger box, the guide being allowed to project between the box and
the cover, and the necessary tension is secured by three rubber
bands around the box as before. In like manner the remaining boxes
are

[Illustration: Appliances for the Disappearing Coin]

adjusted so that finally the prepared nest of boxes appears as in
Fig. 3.

The coin can easily be passed into the inner box through the tin
guide, then the guide can be withdrawn which permits the
respective boxes to close and the rubber bands hold each one in a
closed position.

The performer comes forward with the tin can in his right hand,
the bottom of the can in his palm with the slot at the right side.
He removes the cover with the left hand and passes his wand around
the inner part of the can which is then turned upside down to
prove that it contains nothing. The marked coin is dropped into
the can by some one in the audience. The cover is replaced and the
can shaken so the coin will rattle within. The shaking of the can
is continued until the coin has slipped through the slot into his
palm. The can is then placed on the table with his left hand. Then
apparently he looks for something to cover the can. This is found
to be a handkerchief which was previously prepared on another
table concealing the nest of boxes. The coin in the right hand is
quickly slipped into the guide of the nest of boxes, which was
placed in an upright position, and the guide withdrawn, and
dropped on the table. The performer, while doing this, is
explaining that he is looking for a suitable cover for the can,
but as he cannot find one he takes the handkerchief instead. The
handkerchief is spread over the can and then he brings the nest of
boxes. He explains how he will transfer the coin and passes his
wand from the can to the boxes. The can is then shown to be empty
and the boxes given to one in the audience to be opened. They will
be greatly surprised to find the marked coin within the innermost
box.



** How to Keep Film Negatives [194]

There are many devices for taking care of film negatives to keep
them from curling and in a place easily accessible. Herewith is
illustrated a method by which anyone can make a place for the
negatives produced by his or her special film camera. The device
is made up similar to a post card album with places cut through
each leaf to admit each corner of the negatives. The leaves are
made from white paper and when the negatives are in place the
pictures made on them can

[Illustration: Negatives on White Paper Background]

easily be seen through to the white paper background. These leaves
can be made up in regular book form, or tied together similar to a
loose-leaf book, thus adding only such pages as the negatives on
hand will require.
--Contributed by H. D. Harkins, St. Louis, Mo.



** Home-Made Match Safe [194]

[Illustration: Details of the Match Safe]

Cut a piece of tin in the shape and with the dimensions shown in
Fig. 1. Bend the saw-toothed edges at right angles to the piece on
the dotted lines. Bend the part that is marked 5-1/2 in. in a half
circle. Make a circle 3-1/2 in. in diameter on another piece of
tin, cut out the circle and cut the disk in two as shown in Fig.
2. These half circle pieces are soldered to the sides of the teeth
of the half circle made in the long piece of tin. Remove one end
from the inside box containing matches and slip the back of the
match safe through between the bottom of the inside box and the
open end box that forms the cover. The matches will fall into the
half circle tray at the lower end of the box which will be kept
full of matches until they are all used from the box.
--Contributed by C. F. White, Denver, Colo.



** An Electric Post Card Projector [195]

A post card projector is an instrument for projecting on a screen
in a darkened room picture post cards or any other pictures of a
similar size. The lantern differs from the ordinary magic lantern
in two features; first, it requires no expensive condensing lens,
and second, the objects to be projected have no need of being
transparent.

Two electric globes are made to cast the strongest possible light
on the picture card set between them and in front of which a lens
is placed to project the view on the screen, the whole being
enclosed in a light-tight box. The box can be made of selected oak
or mahogany. The lens to be used as a projector will determine the
size of the box to some extent. The measurements given in these
instructions are for a lens of about 5 in. focal length. The box
should be constructed of well seasoned wood and all joints made
with care so they will be light-tight.

The portion shown carrying the lens in Fig. 1 is made to slide in
the main body of the lantern for focusing. A box should first be
made 5-1/2 in. wide, 5-1/2 in. high and 11 in. long. A hole is cut
in the back of the box 4 by 6 in. represented by the dotted line
in Fig. 2. This will be 3/4 in. from the top and bottom and 2-1/2
in. from each end of the outside of the box. Two strips of wood
1/2 in. wide and 6-1/2 in. long are fastened along the top and
bottom of the back. The door covering this hole in the back, and,
which is also used as a carrier for the post cards, is made from a
board 4-1/2 in. wide and 6-1/2 in. long. The door is hinged to the
lower strip and held in position by a turn button on the upper
strip. The slides for the picture cards are made from strips of
tin bent as shown, and tacked to the inside surface of the door.

The runners to hold the part carrying the lens are two pieces
2-1/4 in. wide by 5 in. long and should be placed

[Illustration: Details of the Post Card Lantern]

vertically, AA, as shown in Fig. 1, 3-1/2 in. from each end. An
open space 4 in. wide and 5 in. high in the center is for the part
carrying the lens to slide for focusing. The part carrying the
lens is a shallow box 4 by 5 in. and 2 in. deep in the center of
which a hole is cut to admit the lens. If a camera lens is used,
the flange should be fastened with screws to the front part of
this shallow box. The sides of this box should be made quite
smooth and a good, but not tight, fit into the runners. Plumbago
can be rubbed on to prevent sticking and to dull any rays of
light.

Two keyless receptacles for electric globes are fastened to the
under side of the top in the position shown and connected with
wires from the outside. Two or three holes about 1 in. in diameter
should be bored in the top between and in a line with the lights.
These will provide ventilation to keep the pictures from being
scorched or becoming buckled from the excessive heat. The holes
must be covered over on the top with a piece of metal or wood to
prevent the light from showing on the ceiling. This piece should
not be more than 1/2 in. high and must

[Illustration: Post Card Lantern Complete]

be colored dead black inside to cause no reflection.

The reflectors are made of sheet tin or nickel-plated metal bent
to a curve as shown, and extending the whole height of the
lantern. The length of these reflectors can be determined by the
angle of the lens when covering the picture. This is clearly shown
by the dotted lines in Fig. 1. The reflectors must not interfere
with the light between the picture and the lens, but they must be
sufficiently large to prevent any direct light reaching the lens
from the lamps. In operation place the post card upside down in
the slides and close the door. Sliding the shallow box carrying
the lens will focus the picture on the screen.



** A Handy Calendar [196]

[Illustration: The Knuckles Designate the 31 Day Months]

"Thirty days hath September, April, June and November," etc., and
many other rhymes and devices are used to aid the memory to decide
how many days are in each month of the year. Herewith is
illustrated a very simple method to determine the number of days
in any month. Place the first finger of your right hand on the
first knuckle of your left hand, calling that knuckle January;
then drop your finger into the depression between the first and
second knuckles, calling this February; then the second knuckle
will be March, and so on, until you reach July on the knuckle of
the little finger, then begin over again with August on the first
knuckle and continue until December is reached. Each month as it
falls upon a knuckle will have 31 days and those down between the
knuckles 30 days with the exception of February which has only 28
days.
--Contributed by Chas. C. Bradley, West Toledo, Ohio.



** The Fuming of Oak [196]

Darkened oak always has a better appearance when fumed with
ammonia. This process is rather a difficult one, as it requires an
airtight case, but the description herewith given may be entered
into with as large a case as the builder cares to construct.

Oak articles can be treated in a case made from a tin biscuit box,
or any other metal receptacle of good proportions, provided it is
airtight. The oak to be fumed is arranged in the box so the fumes
will entirely surround the piece; the article may be propped up
with small sticks, or suspended by a string. The chief point is to
see that no part of the wood is covered up and that all surfaces
are exposed to the fumes. A saucer of ammonia is placed in the
bottom of the box, the lid or cover closed, and all joints sealed
up by pasting heavy brown paper over them. Any leakage will be
detected if the nose is placed near the tin and farther
application of the paper will stop the holes. A hole may be cut in
the cover and a piece of glass fitted in, taking care to have all
the edges closed. The process may be watched through the glass and
the article removed when the oak is fumed to the desired shade.
Wood stained in this manner should not be French polished or
varnished, but waxed.

The process of waxing is simple: Cut some beeswax into fine shreds
and place them in a small pot or jar. Pour in a little turpentine,
and set aside for half a day, giving it an occasional stir. The
wax must be thoroughly dissolved and then more turpentine added
until the preparation has the consistency of a thick cream. This
can be applied to the wood with a rag and afterward brushed up
with a stiff brush.



** How to Make an Electrolytic Rectifier [197]

[Illustration: Electrolytic Rectifier and Connections]

Many devices which will change alternating current to a direct
current have been put on the market, but probably there is not one
of them which suits the amateur's needs and pocketbook better than
the electrolytic rectifier.

For the construction of such a rectifier four 2-qt. fruit jars are
required. In each place two electrodes, one of lead and one of
aluminum. The immersed surface of the aluminum should be about 15
sq. in. and the lead 24 sq. in. The immersed surface of the lead
being greater than that of the aluminum, the lead will have to be
crimped as shown in Fig, 1. In both Fig. 1 and 2, the lead is
indicated by L and the aluminum by A.

The solution with which each jar is to be filled consists of the
following:

    Water             2 qt.
    Sodium Carbonate  2 tablespoonfuls
    Alum              3 tablespoonfuls

Care should be taken to leave the connections made as shown in
Fig. 2. The alternating current comes in on the wires as shown,
and the direct current is taken from the point indicated.

The capacity of this rectifier is from 3 to 5 amperes, which is
sufficient for charging small storage batteries, running small
motors and lighting small lamps.
--Contributed by J. H. Crawford, Schenectady, N. Y.



** The Rolling Marble [197]

Take a marble and place it on a smooth surface, The top of a table
will do. Ask someone to cross their first and second fingers and
place them on the marble as shown in the illustration. Then have
the person roll the marble about and at the same time close the
eyes or look in another direction. The person will imagine that
there are two marbles instead of one.

[Illustration: Rooling Marble]



** A Gas Cannon [197]

If you have a small cannon with a bore of 1 or 1-1/2 in., bore out
the fuse hole large enough to tap and fit in a small sized spark
plug such as used on a gasoline engine. Fill the cannon with gas
from a gas jet and then push a

[Illustration: Gas Cannon Loaded]

cork in the bore close up to the spark plug. Connect one of the
wires from a battery to a spark coil and then to the spark plug.
Attach the other wire to the cannon near the spark plug. Turn the
switch to make a spark and a loud report will follow.
--Contributed by Cyril Tegner, Cleveland, O.



** Old-Time Magic-Part VI [198]



** A Handkerchief Mended after Being Cut and Torn

Two persons are requested to come forward from the audience to
hold the four corners of a handkerchief. Then beg several other
handkerchiefs from the audience and place them on the one held by
the two persons. When several handkerchiefs have been accumulated,
have some one person draw out one from the bunch and examine for
any marks that will determine that this handkerchief is the one to
be mended after being mutilated. He, as well as others, are to cut
off pieces from this handkerchief and to finally tear it to
pieces.

The pieces are then all collected and some magic spirits thrown
over the torn and cut parts; tie them in a small package with a
ribbon and put them under a glass, which you warm with your hands.
After a few seconds' time, you remove the glass, as you have held
it all the time, and take the handkerchief and unfold it; everyone
will recognize the mark and be amazed not to find a cut or tear in
the texture.

This trick is very simple. You have an understanding with some one
in the company, who has two handkerchiefs exactly alike and has
given one of them to a person behind the curtain; he throws the
other, at the time of request for handkerchiefs, on the
handkerchiefs held for use in the performance of the trick. You
manage to keep this handkerchief where it will be picked out in
preference to the others, although pretending to thoroughly mix
them up. The person selected to pick out a handkerchief naturally
will take the handiest one. Be sure that this is the right one.

When the handkerchief has been torn and folded, put it under the
glass, on a table, near a partition or curtain. The table should
be made with a hole cut through the top and a small trap door
fitted snugly in the hole, so it will appear to be a part of the
table top. This trap door is hinged on the under side and opens
into the drawer of the table and can be operated by the person
behind the curtain who will remove the torn handkerchief and
replace it with the good one and then close the trap door by
reaching through the drawer of the table.



** The Magic Knot [198]

This is a very amusing trick which consists of tying one knot with
two ends of a handkerchief, and pulling the

[Illustration: Tying and Untying a Knot]

ends only to untie them again. Take the two diagonal corners of a
handkerchief, one in each hand and throw the main part of the
handkerchief over the wrist of the left hand and tie the knot as
shown in the illustration. Pull the ends quickly, allowing the
loop over the left hand to slip freely, and you will have the
handkerchief without any knot.



** A Good Mouse Trap [198]

When opening a tomato or other small can, cut the cover crossways
from side to side making four triangular pieces in the top. Bend
the four ends outward and remove the contents, wash clean and dry
and then bend the four ends inward, leaving a hole about 3/4 in.
in diameter in the center. Drop in a piece of bread and lay the
can down upon its side and the trap is ready for use. The mouse
can get in but he cannot get out.
--Contributed by E. J. Crocker, Victor, Colo.



** Finishing Aluminum [198]

Rubbing the surface of an aluminum plate with a steel brush will
produce a satin finish.



** How to Make a Sailing Canoe [199]

A canvas canoe is easily made and light to handle, but in making
one, it must be remembered that the cloth will tear, if any snags
are encountered. Therefore such a craft cannot be used in all
waters, but by being careful at shores, it can be used as safely
as an ordinary sailing canoe. Be sure to select the best materials
and when complete cover the seams well with paint.

[Illustration: Completed Sailing Canoe]

The materials necessary for the construction of a sailing canoe,
as illustrated in the engraving, are as follows:

    1 keelson, 1 in. by 8 in. by 15 ft., selected pine.
    14 rib bands, 1 in. square by 16 ft., clear pine.
    2 gunwales, 1 in. by 2 in. by 16 ft.
    1 piece for forms and bow pieces, 1 in. by 12 in. by 10 ft.
    4 outwales, 1/4 in. by 2 in. by 16 ft.
    1 piece, 3 in. wide and 12 ft. long, for cockpit frame.
    1 piece, 2 in. wide and 12 ft. long, for center deck braces.
    11 yd. of 1-1/2-yd. wide 12-oz. ducking.
    8 yd. of 1-yd. wide unbleached muslin.
    50 ft. of rope.
    1 mast, 9 ft. long.
    Paint, screws and cleats.

The keelson, Fig. 1, is 14 ft. long, 8 in. wide in the center and
tapered down from a point 4 ft. from each end to 1 in. at the
ends. Both ends are mortised, one 6 in. for the stern piece, and
the other 12 in. for the bow. Be sure to get the bow and stern
pieces directly in the middle of the keelson and at right angles
with the top edge. The stern and bow pieces are cut as shown in
Fig. 2 and braced with an iron band, 1/8 in. thick and 3/4 in.
wide, drilled and fastened with screws.

Study the sketches showing the details well before starting to cut
out the pieces. Then there will be no trouble experienced later in
putting the parts together. See that all the pieces fit their
places as the work proceeds and apply the canvas with care.

Two forms are made as shown in Figs. 3 and 4; the smaller is
placed 3 ft. from the bow and the large one, 7 ft. 3 in. from the
stern. The larger mould is used temporarily while making the boat,
and is removed after the ribs are in place. The gunwales are now
placed over the forms and in the notches shown, and fastened with
screws, and, after cutting the ends to fit the bow and stern
pieces, they are fastened with bolts put through the three pieces.
The sharp edges on one side of each rib-band are removed and seven
of them fastened with screws to each side of the moulds, spacing
them on the large mould 4 in. apart. The ribs are made of 28 good
barrel hoops

[Illustration: Details of a Home-Made Sailing Canoe]

which should be well soaked in water for several hours before
bending them in shape. These are put in 6 in. apart and are
fastened to the rib-bands with 7/8-in. wood screws. The ribs
should be put in straight and true to keep them from pulling the
rib-bands out of shape. After the ribs are in place and fastened
to the rib-bands, gunwales and keelson, put on the outwale strips
and fasten them to the gunwales between every rib with 1-1/2-in.
screws.

Before making the deck, a block for the mast to rest in must be
made and fastened to the keelson. This block, Fig. 5, is a cube
having sides 6 in. square and is kept from splitting by an iron
band tightly fitted around the outside. The block is fastened to
the keelson, 3-1/2 ft. from the bow, with bolts through
countersunk holes from the under side.

There are three deck braces made as shown in Figs. 6, 7 and 8.
Braces, Figs. 6 and 7, form the ends of the cockpit which is 20
in. wide. A 6-in. board is fitted into the mortises shown in these
pieces; a center piece is fitted in the other mortises. The other
deck braces slope down from the center piece and are placed 6 in.
apart. They are 1 in. square and are mortised into the center
piece and fastened to the gunwales with screws. The main deck
braces are fastened to the gunwales with 4-in. corner braces and
to the center piece with 2-in. corner braces. The mast hole on the
deck is made as follows: Secure a piece of pine 1 in. thick, 6 in.
wide and 3 ft. long. Cut this in halves and mortise for the center
piece in the two halves and fasten to the gunwales. A block of
pine, 4 in. thick and 12 in. long, is cut to fit under the top
boards, Fig. 9, and fastened to them with bolts. With an expansive
bit bore a hole 3 in. in diameter through the block. Be sure to
get the block and hole directly over the block that is fastened to
the keelson. Put on a coat of boiled linseed oil all over the
frame before proceeding farther.

Putting on the canvas may be a difficult piece of work to do, yet
if the following simple directions are followed out no trouble
will be encountered. The 11-yd. length of canvas is cut in the
center, doubled, and a seam made joining the two pieces together.
Fill the seam with thick paint and tack it down with copper tacks
along the center of the keelson. When this is well tacked commence
stretching and pulling the canvas in the middle of the gunwales so
as to make it as even and tight as possible and work toward each
end, tacking the canvas as it is stretched to the outside of the
gunwale. Seam the canvas along the stern and bow pieces as was
done on the keelson. The deck is not so hard to do, but be careful
to get the canvas tight and even. A seam should be made along the
center piece. The trimming is wood, 1/4 in. thick and 1/2 in.
wide. A strip of this is nailed along the center piece over the
canvas. The outwales are nailed on over the canvas. A piece of
oak, 1 in. thick 1-1/2 in. wide and 14 in. long, is fastened with
screws over the canvas on the stern piece; also, a piece 1/4 in.
thick, 1 in. wide and 24 in. long is well soaked in water, bent to
the right shape and fastened over the canvas on the bow.

The rudder is made as shown in Fig. 10 with a movable handle. A
strip 1 in. thick by 2 in. wide, is bolted to the keelson over the
canvas for the outer keel. The keel, Fig. 11, is 6 in. wide at one
end and 12 in. at the other, which is fastened to the outer keel
with bolts having thumb nuts. The mast can be made of a young
spruce tree having a diameter of 3 in. at the base with sufficient
height to make it 9 ft. long. The canoe is driven by a lanteen
sail and two curtain poles, each 1 in. in diameter and 10 ft.
long, are used for the boom and gaff, which are held together with
two pieces of iron bent as shown in Fig. 12. The sail is a
triangle, 9-3/4 by 9-3/4 by 8-1/2 ft. which is held to the boom
and gaff by cord lacings run through eyelets inserted in the
muslin. The eyelets are of brass placed 4 in. apart in the muslin.
The mast has two side and one front stay, each fitted with a
turnbuckle for tightening. A pulley is placed at the top and
bottom of the mast for the lift rope. The sail is held to the mast
by an iron ring and the lift rope at the top of the mast. The boom
rope is held in the hand and several cleats should be placed in
the cockpit for convenience. A chock is placed at the bow for
tying up to piers. Several coats of good paint complete the boat.
--Contributed by O. E. Tronnes, Wilmette, Ill.



** A Home-Made Hand Vise [201]

A very useful little hand vise can easily be made from a hinge and
a bolt carrying a wing nut. Get a fast

[Illustration: Hand Vise Made from a Hinge]

joint hinge about 2 in. or more long and a bolt about 1/2 in. long
that will fit the holes in the hinge. Put the bolt through the
middle hole of the hinge and replace the nut as shown in the
drawing. With this device any small object may be firmly held by
simply placing it between the sides of the hinge and tightening
the nut.



** Proper Design for a Bird House [201]

This bird house was designed and built to make a home for the
American martin. The house will accommodate 20 families. All the
holes are arranged so they will not be open to the cold winds from
the north which often kill the birds which come in the early
spring. Around each opening is an extra ring of wood to make a
longer passage which assists the martin inside in fighting off the
English

[Illustration: Bird House]

sparrow who tries to drive him out. The holes are made oval to
allow all the little ones to get their heads out for fresh air.
The long overhanging eaves protect the little birds from the hot
summer sun. The rooms are made up with partitions on the inside so
each opening will have a room. The inside of the rooms should be
stained black.



** Boomerangs and How to Make Them [202]

A boomerang is a weapon invented and used by the native
Australians, who seemed to have the least intelligence of any race
of mankind. The

[Illustration: Details of Three Boomerangs]

boomerang is a curved stick of hardwood, Fig. 1, about 5/16 in.
thick, 2-1/2 in. wide and 2 ft. long, flat on one side, with the
ends and the other side rounding. One end of the stick is grasped
in one hand with the convex edge forward and the flat side up and
thrown upward. After going some distance and ascending slowly to a
great height in the air with a quick rotary motion, it suddenly
returns in an elliptical orbit to a spot near the starting point.
If thrown down on the ground the boomerang rebounds in a straight
line, pursuing a ricochet motion until the object is struck at
which it was thrown.

Two other types of boomerangs are illustrated herewith and they
can be made as described. The materials necessary for the T-shaped
boomerang are: One piece of hard maple 5/16 in. thick, 2-1/2 in.
wide, and 3 ft. long; five 1/2-in. flat-headed screws. Cut the
piece of hard maple into two pieces, one 11-1/2 in. and the other
18 in. long. The corners are cut from these pieces as shown in
Fig. 2, taking care to cut exactly the same amount from each
corner. Bevel both sides of the pieces, making the edges very thin
so they will cut the air better. Find the exact center of the long
piece and make a line 1-1/4 in. on each side of the center and
fasten the short length between the lines with the screws as shown
in Fig. 3. The short piece should be fastened perfectly square and
at right angles to the long one.

The materials necessary for the cross-shaped boomerang are one
piece hard maple 5/16 in. thick, 2 in. wide and 30 in. long and
five 1/2-in. flat headed screws. Cut the maple- into two 14-in.
pieces and plane the edges of these pieces so the ends will be
1-1/2 in. wide, as shown in Fig. 4. Bevel these pieces the same as
the ones for the T-shaped boomerang. The two pieces are fastened
together as shown in Fig. 5. All of the boomerangs when completed
should be given several coats of linseed oil and thoroughly dried.
This will keep the wood from absorbing water and becoming heavy.
The last two boomerangs are thrown in a similar way to the first
one, except that one of the pieces is grasped in the hand and the
throw given with a quick underhand motion. A little practice is
all that is necessary for one to become skillful in throwing them.
--Contributed by O. E. Tronnes, Wilmette, Ill.



** How to Make Water Wings [202]

Purchase a piece of unbleached muslin, 1 yd. square. Take this and
fold it over once, forming a double piece 1-1/2 ft. wide and 3 ft.
long. Make a double stitch all around the edge, leaving a small
opening at one corner. Insert a piece of tape at this corner to be
used for tying around the opening when the bag is blown up. The
bag is then turned inside out, soaked with water and blown up. An
occasional wetting all over will prevent it from leaking. As these
wings are very large they will prevent the swimmer from sinking.
--Contributed by W. C. Bliss, St. Louis, Mo.



** How to Make an Ammeter [203]

The outside case of this instrument is made of wood taken from old
cigar boxes with the exception of the back. If carefully and
neatly made, the finished instrument will be very satisfactory.
The measurements here given need not be strictly followed out, but
can be governed by circumstances. The case should first be made
and varnished and while this is drying, the mechanical parts can
be put together.

[Illustration: Details of an Ammeter]

The back is a board 3/8 in. thick, 6-1/2 in. wide and 6-3/4 in.
long. The outer edges of this board are chamfered. The other parts
of the case are made from the cigar box wood which should be well
sandpapered to remove the labels. The sides are 3-1/4 in. wide and
5 in. long; the top and bottom, 3-1/4 in. wide and 4-1/2 in. long.
Glue a three cornered piece, A, Fig. 1, at each end on the surface
that is to be the inside of the top and bottom pieces. After the
glue, is set, fasten the sides to the pieces with glue, and take
care that the pieces are all square. When the glue is set, this
square box is well sandpapered, then centered, and fastened to the
back with small screws turned into each three-cornered piece.

The front, which is a piece 5-1/4 in. wide and 6-1/2 in. long, has
a circular opening cut near the top through which the graduated
scale may be seen. This front is centered and fastened the same as
the back, and the four outside edges, as well as the edges around
the opening, are rounded. The whole case can now be cleaned and
stained with a light mahogany stain and varnished. Cut another
piece of board, B, Figs. 2 and 3, to just fit inside the case and
rest on the ends of the three-cornered pieces, A, and glue to this
board two smaller pieces, C, 3 in. square, with the grain of the
wood in alternate directions to prevent warping. All of these
pieces are made of the cigar box wood. Another piece, D, 3/8 in.
thick and 3 in. square, is placed on the other pieces and a
U-shaped opening 1-3/4 in. wide and 2-1/2 in. high sawed out from
all of the pieces as shown. The piece D is attached to the pieces
C with four 1/2-in. pieces 2-5/8 in. long.

A magnet is made from a soft piece of iron, E, about 3/8 in.
thick, 1-1/4 in. wide and 2-3/4 in. long. Solder across each end
of the iron a piece of brass wire, F, and make a turn in each end
of the wires, forming an eye for a screw. These wires are about
2-1/2 in. long. Wind three layers of about No. 14 double
cotton-covered copper wire on the soft iron and leave about 5 or 6
in. of each end unwound for connections.

The pointer is made as shown in Fig. 5 from 1/16-in. brass wire
filed to make a point at both ends for a spindle. About 1/2 in.
from each end of this wire are soldered two smaller brass wires
which in turn are soldered to a strip of light tin 1/4 in. wide
and 2-5/8 in. long. The lower edge of this tin should be about 1/2
in. from the spindle. The pointer is soldered to the spindle 1/4
in. from one end. All of these parts should be brass with the
exception of the strip of tin. Another strip of tin, the same size
as the first, is soldered to two brass wires as shown in Fig. 4.
These wires should be about 1 in. long.

The spindle of the pointer swings freely between two bars of
brass, G, 1/16 in. thick, 1/4 in. wide and 2-1/2 in. long. A small
hole is countersunk in one of the bars to receive one end of the
spindle and a hole 1/8 in. in diameter is drilled in the other and
a thumb nut taken from the binding-post of an old battery soldered
over the hole so the screw will pass through when turned into the
nut. The end of the screw is countersunk to receive the other end
of the spindle. A lock nut is necessary to fasten the screw when
proper adjustment is secured. A hole is drilled in both ends of
the bars for screws to fasten them in place. The bar with the
adjusting screw is fastened on the back so it can be readily
adjusted through the hole H, bored in the back. The pointer is
bent so it will pass through the U-shaped cut-out and up back of
the board B. A brass pin is driven in the board B to hold the
pointer from dropping down too far to the left. Place the tin,
Fig. 4, so it will just clear the tin, Fig. 5, and fasten in
place. The magnet is next placed with the ends of the coil to the
back and the top just clearing the tin strips. Two binding screws
are fitted to the bottom of the back and connected to the
extending wires from the coil.

The instrument is now ready for calibrating. This is done by
connecting it in series with another standard ammeter which has
the scale marked in known quantities. In this series is also
connected a variable resistance and a battery or some other source
of current supply. The resistance is now adjusted to show .5
ampere on the standard ammeter and the position of the pointer
marked on the scale. Change your resistance to all points and make
the numbers until the entire scale is complete.

When the current flows through the coil, the two tinned strips of
metal are magnetized, and being magnetized by the same lines of
force they are both of the same polarity. Like poles repel each
other, and as the part Fig. 4 is not movable, the part carrying
the pointer moves away. The stronger the current, the greater the
magnetism of the metal strips, and the farther apart they will be
forced, showing a greater defection of the pointer. --Contributed
by George Heimroth, Richmond Hill, L. I.



** How to Make an Equatorial [204] Condensed from article
contributed by J. R. Chapman, F.R.A.S. Austwick Hall. W.
Yorkshire. England

This star finder can easily be made by anyone who can use a few
tools as the parts are all wood and the only lathe work necessary
is the turned shoulder on the polar axis and this could be dressed
and sandpapered true enough for the purpose. The base is a board 5
in. wide and 9 in. long which is fitted with an ordinary wood
screw in each corner for leveling. Two side pieces cut with an
angle equal to the colatitude of the place are nailed to the base
and on top of them is fastened another board on which is marked
the hour circle as shown. The end of the polar axis B, that has
the end turned with a shoulder, is fitted in a hole bored in the
center of the hour circle. The polar axis B is secured to the
board with a wooden collar and a pin underneath. The upper end of
the polar axis is fitted with a 1/4-in. board, C, 5-1/2 in. in
diameter. A thin compass card divided into degrees is fitted on
the edge of this disk for the declination circle.

The hour circle A is half of a similar card with the hour marks
divided into 20 minutes. An index pointer is fastened to the base
of the polar axis. A pointer 12 in. long is fastened with a small
bolt to the center of the declination circle. A small opening is
made in the pointer into which an ordinary needle is inserted.
This needle is adjusted to the degree to set the pointer in
declination and when set, the pointer is clamped with the bolt at
the center. A brass tube having a 1/4-in. hole is fastened to the
pointer.

The first thing to do is to get a true N and S meridian mark. This
can be approximately obtained by a good compass, and allowance
made for the magnetic declination at your own place. Secure a slab
of stone or some other solid flat surface, level this and have it
firmly fixed facing due south with a line drawn through the center
and put the equatorial on the surface with XII on the south end of
the line. Then set the pointer D to the declination of the object,
say Venus at the date of observation. You now want to know if this
planet is east or west of your meridian at the time of
observation. The following formula will show how this may be
found. To find a celestial object by equatorial: Find the planet
Venus May 21, 1881, at 9 hr. 10 min. A. M. Subtract right
ascension of planet from the time shown by the clock, thus:


                                     hour   minute  second
  9 hr. 10 min. shows mean siderial.   1      0       0
  Add 12 hrs                          12
                                      ---    ---     ---
                                      13


  Right ascension of Venus             2      10
                                      ---    ---     ---
  Set hour circle to before meridian  10      50      0
  Again------------------
  At 1 hr. 30 min. mean clock shows    5      20      0
  Right ascension of Venus             2      10      0
                                      ---     ---    ---
  Set hour circle to                   3      10      0

Books may be found in libraries that will give the right ascension
and declination of most of the heavenly bodies.

The foregoing tables assume that you have a clock rated to
siderial time,

[Illustration: Home-Made Equatorial]

but this is not absolutely necessary. If you can obtain the
planet's declination on the day of observation and ascertain when
it is due south, all you have to do is to set the pointer D by the
needle point and note whether Venus has passed your meridian or
not and set your hour index. There will be no difficulty in
picking up Venus even in bright sunlight when the plant is visible
to the naked eye.



** Electric Light Turned On and Off from Different Places [205]

How nice it would be to have an electric light at the turn in a
stairway, or at the top that could be turned on before starting up
the stair and on reaching the top turned out, and vice

[Illustration: The Wiring Diagram]

versa when coming down. The wiring diagram as shown in the
illustration will make this a pleasant reality. This wiring may be
applied in numerous like instances. The electric globe may be
located at any desired place and the two point switches are
connected in series with the source of current as shown in the
sketch. The light may be turned on or off at either one of the
switches.
--Contributed by Robert W. Hall, New Haven, Conn.



** How to Make a Bunsen Cell [206]

This kind of a cell produces a high e.m.f. owing to the low
internal resistance. Procure a glass jar such as used for a
gravity battery, or, if one of these cannot be had, get a glazed
vessel of similar construction. Take a piece of sheet zinc large
enough so that when it is rolled up in the shape of a cylinder it
will clear the edge of the jar by about 1/2 in. Solder a wire or
binding-post to the edge of the cylinder for a connection.

[Illustration: Cross Section and Completed Cell]

Secure a small unglazed vessel to fit inside of the zinc, or such
a receptacle as used in a sal ammoniac cell, and fill it with a
strong solution of nitric acid. Fill the outer jar with a solution
of 16 parts water and 5 parts sulphuric acid. The connections are
made from the zinc and carbon.



** Optical Illusion [206]

Can you tell which of these three figures is the tallest? Make a
guess, and then verify its correctness by measurement.

[Illustration: Who is tallest?]



** One Way to Cook Fish [206]

One of the best and easiest ways of cooking fish while out camping
is told by a correspondent of Forest and Stream. A fire is built
the size for the amount of food to be cooked and the wood allowed
to burn down to a glowing mass of coals and ashes. Wash and season
your fish well and then wrap them up in clean, fresh grass, leaves
or bark. Then, after scraping away the greater part of the coals,
put the fish among the ashes, cover up with the same, and heap the
glowing coals on top. The fish cooks quickly--15 or 20
minutes--according to their size.

If you eat fish or game cooked after this fashion you will agree
that it cannot be beaten by any method known to camp culinary
savants. Clay also answers the purpose of protecting. the fish or
game from the fire if no other material is at hand, and for
anything that requires more time for cooking it makes the best
covering. Wet paper will answer, especially for cooking fish.



** Hardening Copper [206]

A successful method of hardening copper is to add 1 lb. of alum
and 4 oz. arsenic to every 20 lb. of melted copper and stir for 10
minutes.



** Packing Cut from Felt Hats [206]

Felt from an old hat makes good packing for automobile
water-circulating pumps. Strips should be cut to fit snugly in the
stuffing box. When the follower is screwed down, it will expand
the felt and make a watertight joint.



** Homemade Gasoline Engine [206]

The material used in the construction of the gasoline engine, as
shown in the accompanying picture, was pieces found in a scrap
pile that usually occupies a fence corner on almost every farm.
The cylinder consists of

[Illustration: Complete Homemade Gasoline Engine]

an old pump cylinder, 3/8 in. thick, 1-3/4 in. inside diameter and
about 5 in. long. This was fastened between some wooden blocks
which were bolted on the tool carriage of a lathe and then bored
out to a diameter of about 2 in. The boring bar, Fig. 1, consisted
of an old shaft with a hole bored through the center and a tool
inserted and held for each cut by a setscrew. A wood mandrel with
a metal shaft to turn in the centers of a lathe was made to fit
the bored-out cylinder. The cylinder was then placed on the
mandrel, fastened with a pin, and threaded on both ends. Flanges
were next made from couplings discarded from an old horsepower
tumbling rod, to fit on the threaded ends of the cylinder casting.
When these flanges were tightly screwed on the casting and faced
off smooth the whole presented the appearance of a large spool.

The back cylinder head was made from a piece of cast iron, about
1/2 in. thick, turned to the same diameter as the flanges, and
with a small projection to fit snugly inside the cylinder bore.
Two holes were then drilled in this head and tapped for 3/4-in.
pipe. Two pieces of 3/4 -in. pipe were fitted to these holes so
that, when they were turned in, a small part of the end of each
pipe projected on the inside of the cylinder head. These pieces of
pipe serve as valve cages and are reamed out on the inside ends to
form a valve seat. The outlet for the exhaust and the inlet for
the gas and air are through holes drilled in the side of each pipe
respectively and tapped for 1/2-in. pipe. Two heads were then made
to fit over the outer ends of the valve cages. These heads looked
similar to a thread spool with one flange cut off, the remaining
flange fitting on the

[Illustration: Steps in Making the Home-Made Gasoline Engine]

end of the valve cage and the center extending down inside to make
a long guide for the valve stems. These heads are held in place by
a wrought-iron plate and two bolts, one of which is plainly shown
in the picture. This plate also supports the rocker arms, Fig. 2,
and the guides for the rods that operate the valves. Both valves
are mechanically operated by one cam attached to a shaft running
one turn to two of the crankshaft. The gears to run this shaft
were cut from solid pieces on a small home-made gear-cutting
attachment for the lathe as shown in Fig. 3. The gear on the
crankshaft has 20 teeth meshing into a 40-tooth gear on the cam
shaft.

The main part of the frame consists of a piece of 1/2-in. square
iron, 30 in. long, bent in the shape of a U, and on the outside of
this piece is riveted a bent piece of sheet metal 1/8 in. thick
and 3 in. wide. The U-shaped iron is placed near one edge of the
sheet metal. Two pieces of 2-1/2-in. angle iron are riveted
vertically on the ends of the U-shaped iron and a plate riveted on
them to close the open end and to form a face on which to attach
the cylinder with bolts or cap screws. A hole was cut through the
angle irons and plate the same size as the bore of the cylinder so
the piston could be taken out without removing the cylinder. A
1-in. angle iron was riveted to one side of the finished frame to
make a support for the crankshaft bearing. The rough frame, Fig.
4, was then finished on an emery wheel. This long frame had to be
made to accommodate the crosshead which was necessary for such a
short cylinder.

The piston and rod were screwed together and turned in one
operation on a lathe. The three rings were made from an old
cast-iron pulley. The cap screws were made from steel pump rods. A
piece of this rod was centered in a lathe and turned so as to
shape six or more screws, Fig. 5, then removed and the first one
threaded and cut off, then the second and so on until all of them
were made into screws. The rod was held in a vise for this last
operation. Studs were made by threading both ends of a proper
length rod. Make-and-break ignition is used on the engine;
however, a jump spark would be much better. The flywheel and
mixing valve were purchased from a house dealing in these parts.
The water jacket on the cylinder is a sheet of copper formed and
soldered in place, and brass bands put on to co v e r the soldered
joints.
--Contributed by Peter Johnson, Clermont, Iowa.



** Dripping Carburetor [208]

If gasoline drips from the carburetor when the engine is not
running, the needle valve connected with the float should be
investigated. If the dripping stops when the valve is pressed
down, the float is too high. If the valve keeps dripping, then it
should be ground to a fit.



** A Merry-Go-Round Thriller [209]

[Illustration: Swinging on the Merry-Go-Round]

As a home mechanic with a fondness for amusing the children I have
seen many descriptions of merry-go-rounds, but never one which
required so little material, labor and time, and which gave such
satisfactory results, as the one illustrated herewith. It was
erected in our back yard one afternoon, the materials being
furnished by an accommodating lumber pile, and a little junk, and
it has provided unlimited pleasure for "joy-riders," little and
big, from all over the neighborhood. It looks like a toy, but once
seat yourself in it and begin to go around, and, no matter what
your age or size may be, you will have in a minute enough thrill
and excitement to last the balance of the day.

The illustration largely explains itself, but a few dimensions
will be a help to anyone wishing to construct the apparatus. The
upright is a 4 by 4-in. timber, set 3 ft. in the ground with 8 ft.
extending above. It is braced on four sides with pieces 2 in.
square and 2 ft. long, butting against short stakes. The upper end
of the post is wound with a few rounds of wire or an iron strap to
prevent splitting. The crosspiece is 2 in. square, 12 ft. long,
strengthened by a piece 4 in. square and 5 ft. long. These two
pieces must be securely bolted or spiked together. A malleable
iron bolt, 3/4 in. in diameter and 15 in. long is the pivot. On
this depends the safety of the contrivance, so it must be strong
enough, and long enough to keep firmly in the post. Drive this
bolt in a 3/8-in. hole bored in the post, which will make it a
sufficiently tight fit. Make the hole for the bolt very loose
through the crosspiece, so that there will be plenty of "wobble,"
as this is one of the mirth-making features of the machine. Use a
heavy washer at the head. The seats are regular swing boards,
supported by a stout and serviceable rope. A 3/4 -in. rope is not
too heavy. One set of ropes are passed through holes at the end of
the crosspiece and knotted on top. The other set should be
provided with loops at the top and slid over the crosspiece, being
held in position by spikes as shown. This makes an easy
adjustment. Seat the heavier of the riders on the latter seat,
moving it toward the center until a balance with the lighter rider
is reached. A rope tied to the crosspiece about 2 ft. from the
center, for the "motive power" to grasp, completes the
merry-go-round.

Put plenty of soap or grease between the crosspiece and upright.
Be sure to have room for the ropes to swing out at high speed,
with no trees or buildings in the way. The "wobble" mentioned will
give an agreeable undulating motion, which adds greatly to the
flying sensation. This will be found surprisingly evident for so
small a machine. As there is no bracing, care must be taken to
have the two riders sit at the same moment, or the iron bolt will
be bent out of line. If it is to be used for adults, strong clear
material only should be employed.
--Contributed by C. W. Nieman.



** How to Make and Fly a Chinese Kite [210]

The Chinese boy is not satisfied with simply holding the end of a
kite string and running up and down the block or field trying to
raise a heavy paper kite with a half pound of rags for a tail. He
makes a kite as light as possible without any tail which has the
peculiar property of being able to move in every direction.
Sometimes an expert can make one of these kites travel across the
wind for several hundred feet; in fact, I have seen boys a full
block apart bring their kites together and engage

[Illustration: Parts of a Chinese Kite]

in a combat until one of their kites floated away with a broken
string, or was punctured by the swift dives of the other, and sent
to earth, a wreck.

The Chinese boy makes his kite as follows:

From a sheet of thin but tough tissue paper about 20 in. square,
which he folds and cuts along the dotted line, as shown in Fig. 1,
he gets a perfectly square kite having all the properties of a
good flyer, light and strong. He shapes two pieces of bamboo, one
for the backbone and one for the bow. The backbone is flat, 1/4 by
3/32 in. and 18 in. long. This he smears along one side with
common boiled rice. Boiled rice is one of the best adhesives for
use on paper that can be obtained and the Chinese have used it for
centuries while we are just waking up to the fact that it makes
fine photo paste. Having placed the backbone in position, paste
two triangular pieces of paper over the ends of the stick to
prevent tearing. The bow is now bent, and the lugs extending from
the sides of the square paper are bent over the ends of the bow
and pasted down. If the rice is quite dry or mealy it can be
smeared on and will dry almost immediately, therefore no strings
are needed to hold the bow bent while the paste dries.

After the sticks are in position the kite will appear as shown in
Fig. 2. The dotted lines show the lugs bent over the ends of the
bow and pasted down. Figure 3 shows how the band is put on and how
the kite is balanced. This is the most important part and cannot
be explained very well. This must be done by experimenting and it
is enough to say that the kite must balance perfectly. The string
is fastened by a slip-knot to the band and moved back and forth
until the kite flies properly, then it is securely fastened.

A reel is next made. Two ends--the bottoms of two small peach
baskets will do--are fastened to a dowel stick or broom handle, if
nothing better is at hand. These ends are placed about 14 in.
apart and strips nailed between them as shown in Fig. 4, and the
centers drawn in and bound with a string. The kite string used is
generally a heavy packing thread. This is run through a thin flour
or rice paste until it is thoroughly coated, then it is run
through a quantity of crushed glass. The glass should be beaten up
fine and run through a fine sieve to make it about the same as
No.2 emery. The particles should be extremely sharp and full of
splinters. These particles adhere to the pasted string and when
dry are so sharp that it cannot be handled without scratching- the
fingers, therefore the kite is flown entirely from the reel. To
wind the string upon the reel, all that is necessary is to lay one
end of the reel stick in the bend of the left arm and twirl the
other end between the fingers of the right hand.

A Chinese boy will be flying a gaily colored little kite from the
roof of a house (if it be in one of the large cities where they
have flat-roofed houses) and a second boy will appear on the roof
of another house perhaps 200 ft. away. Both have large reels full
of string, often several hundred yards of it. The first hundred
feet or so is glass-covered string, the balance, common packing
thread, or glass-covered string. As soon as the second boy has his
kite aloft, he begins maneuvering to drive it across the wind and
over to the first kite. First, he pays out a large amount of
string, then as the kite wobbles to one side with its nose
pointing toward the first kite, he tightens his line and commences
a steady quick pull. If properly done his kite crosses over to the
other and above it. The string is now payed out until the second
kite is hanging over the first one's line. The wind now tends to
take the second kite back to its parallel and in so doing makes a
turn about the first kite's string. If the second kite is close
enough, the first tries to spear him by swift dives. The second
boy in the meantime is see-sawing his string and presently the
first kite's string is cut and it drifts away.

It is not considered sport to haul the other fellow's kite down as
might be done and therefore a very interesting battle is often
witnessed when the experts clash their kites.
--Contributed by S. C. Bunker, Brooklyn, N. Y.



** Home-Made Vise [211]

An ordinary monkey wrench that has been discarded is used in
making this vise. The wrench is supported by two L-shaped pieces
of iron fastened with

[Illustration: A Swivel Bench Vise]

a rivet through the end jaw, and these in turn are bolted or
screwed to the bench. The handle end is held down with a staple.
The inside jaw is used in clamping and is operated with the thumb
screw of the wrench. Two holes bored through the thumb piece will
greatly facilitate setting up the jaws tightly by using a small
rod in the holes as a lever.

The vise may be made into a swing vise if the wrench is mounted on
a board which is swung on a bolt at one end and held with a pin at
the other as shown in the illustration. Various holes bored in the
bench on an arc will permit the board to be set at any angle.
--Contributed by Harry S. Moody, Newburyport. Mass.



** Home-Made Changing Bag for Plate Holders [212]

A good bag for changing plates and loading plate holders and one
that the operator can see well to work in can

[Illustration: Made of Black Cambric]

be made by anyone on a sewing machine. Ten yards of black cambric
or other black cloth and a little ruby fabric will be required.
Take the cambric and fold it into 2-yd. lengths (Fig. 1) which
will make five layers of cloth, tack or fasten the layers together
so they will not slip and cut an 8-in. square hole in the middle
of one half (Fig. 2) and sew the ruby fabric over the opening. Be
sure and make the seam light-tight and have enough layers of ruby
fabric so no white light can get in. Fold the cloth up so it will
be 1 yd. square (Fig. 3) and sew up the edges to make a bag with
one side open. Put a drawstring in the edge of the cloth around
the open side and the bag is complete ready for use.

Take the holders and plate boxes in the lap and put the bag over
the head and down around the body, then draw the string up tight.
A bag made up in this manner is for use only for a short time. If
it is necessary to do considerable work at a time, then a dust
protector, such as mill men use, must be attached to a 3-ft.
length of 2-in. rubber hose and the hose run through a hole in the
bag. This will make it possible to work in the bag as long as you
wish.
--Contributed by Earl R. Hastings, Corinth, Vt.



** Home-Made Asbestos Table Pads [212]

Asbestos table pads to prevent the marring of polished table tops
from heated dishes can be easily made at home much cheaper than
they can be bought. Procure a sheet of asbestos from a plumbing
shop and cut it in the shape of the top of your table. If the
table is round, make the pad as shown in the illustration, cutting
the circular piece into quarters. Cut four pieces of canton
flannel. each the size of half the table top. Two of the asbestos
pieces are used to make one-half of the pad. Place the two pieces
with their edges together so they will form half a circle disk and
cover both sides with a piece of the flannel and pin them in
place. A binding of white cotton tape is then basted around the
edges to hold all the pieces together until they are stitched on a
sewing machine. A line of machine stitching is made all around the
outside and through the middle

[Illustration: Pads Made of Asbestos]

between where the edges of the asbestos sheets join together. This
will form a hinge so the two quarters may be folded for putting
away. Make the other half circular disk in the same way. If leaves
are wanted in extending the table, any number of pads can be made
to cover them in the same manner with the hinge in the middle of
each pad. The flannel is used with the nap side out so it will
make the pad soft and noiseless. This kind of a pad furnishes
perfect protection to the table from any heat or moisture.
--Contributed by H. E. Wharton, Oakland, Calif.



** How to Make a Ladies' Handbag [213]

To make this bag, get a piece of Russian calf modeling leather. A
shade of brown is the best as it does not soil easily and does not
require coloring, which spoils the leather effect.

The dimensions of the full sized bag are: from A to B, 17-1/2 in.;
from C to D, 16-1/4 in.; from E to F,9-1/4 in.; G to H, 6-1/4 in.,
and E to G, 2-1/4 in.

Enlarge the accompanying pattern to the given dimensions, trace
this or some other appropriate design on it, and then cut the
leather the size of the pattern.

Use a sponge to dampen the leather on the rough side, not so damp
that the water will come through to the right side when working,
but damp enough to allow the design to be well impressed

[Illustration: Pattern]

on the leather. Use a smooth, non-absorbent surface to lay the
leather on while at work.

Now lay the pattern on the right side of the leather and with the
smallest end of the leather tool or a sharp, hard pencil, trace
the design carefully on the leather. Moisten the leather as

[Illustration: Design on the Leather]

often as necessary to keep it sufficiently moist to work well.
Trace the openings for the handles, also lines A-G, H-B, and E-G,
G-J, and corresponding lines on the other side.

Remove pattern and trace the design directly on leather with the
round point of tool, until it is made distinct and in marked
contrast to the rest of the leather. Do not make sharp marks but
round the edges of the lines nicely, with the rounded sides of the
tools.

To complete the bag, get something with which to make a lining. A
piece of oozed leather is the most satisfactory. Cut it the same
size as the bag, place both together and with a leather punch,
make holes all around the edge of the bag about 1/8 in. apart. Cut
out the leather for the handle openings. Care should be taken not
to cut the holes too near the edge of the bag lest the lacing pull
out. Now cut narrow thongs, about 1/8 in. wide, and lace through
the holes, lacing the sides of the end pieces in with the sides of
the bag. Crease the lines A-G and B-H inward for ends of bag.



** Removing Wire Insulation [213]

The claw of a hammer can be used for removing the insulation on
copper wire, if not more than 1 in. is taken off at a time.



** A Small Electric Motor [214]

The drawing herewith shows a simple electric motor which can be
easily constructed by any boy who is at all handy with tools. I
made this motor

[Illustration: Electro-Magnet Motor]

many times when a boy and can say that if carefully constructed it
will run with greater rapidity than the more expensive ones.

A common magnet which can be purchased at any toy store is used.
The one shown is 3-1/2 in. in length. The armature core is a strip
of 1/16 by 1/4-in. iron, 2-1/4 in. long, bent U-shaped and
fastened to the wood flywheel. Each leg of the armature is wound
with 10 ft. of No. 24 gauge magnet wire. The commutator is made
from an old 22 cartridge filed into two equal parts, each being a
half circle, both of which are made fast to a collar on the shaft
E. Each half of the commutator must be insulated from the other
half. The collar can be made by wrapping paper around the shaft
until the required size is obtained.

The top end of the shaft runs in a hole bored in a brass support,
B, which is screwed on the end of a piece of wood mortised in the
base, as shown in Fig. 1. The lower end of the shaft runs in a
glass bead, D, which is fastened to a small piece of brass with
sealing wax. The small brass piece is fastened to the base with
screws. The bead should not have an eye larger in diameter than
the shaft. The shaft is made from an old discarded knitting
needle. The brushes are fastened to each side of the upright piece
of wood supporting the brass bearing B.

The connections to the battery are shown in Fig. 2. Each half of
the commutator C is connected to the coils AA as shown in Fig. 1.
--Contributed by J.M. Shannon, Pasadena, Calif.



** Moving a Coin Under a Glass [214]

Place a penny or a dime on a tablecloth, towel or napkin and cover
it over with a glass in such a way that the glass will rest upon
two 25 or 50 cent pieces as shown in the sketch. The coin is made
to come forth without touching it or sliding a stick under the
edge of the glass. It is only necessary to claw the cloth near the
glass with the nail of the forefinger.

[Illustration: Removing the Coin]

The cloth will produce a movement that will slide the coin to the
edge and from under the glass.



** Improving Phonograph Sound [214]

When playing loud and harsh records on a phonograph the music is
often spoiled by the vibration of the metal horn. This may be
remedied by buckling a valise or shawl strap around the horn, near
the center.



** How to Make Paper Balloons [215]

Balloons made spherical, or designed after the regular aeronaut's
hot-air balloon, are the best kind to make. Those having an odd or
unusual shape will not make good ascensions, and in most


[Illustration: Paper Balloon;  Pattern and Parts to Make Balloon]

cases the paper will catch fire from the torch and burn before
they have flown very far. The following description is for making
a tissue-paper balloon about 6 ft. high.

The paper may be selected in several colors, and the gores cut
from these, pasted "in alternately, will produce a pretty array of
colors when the balloon is in flight. The shape of a good balloon
is shown in Fig. 1. The gores for a 6-ft. balloon should be about
8 ft. long or about one-third longer than the height of the
balloon. The widest part of each gore is 16 in. The widest place
should be 53-1/2 in. from the bottom end, or a little over half
way from the bottom to the top. The bottom of the gore is
one-third the width of the widest point. The dimensions and shape
of each gore are shown in Fig. 2.

The balloon is made up of 13 gores pasted together, using about
1/2-in. lap on the edges. Any good paste will do--one that is made
up of flour and water well cooked will serve the purpose. If the
gores have been put together right, the pointed ends will close up
the top entirely and the wider bottom ends will leave an opening
about 20 in. in diameter. A light wood hoop having the same
diameter as the opening is pasted to the bottom end of the gores.
Two cross wires are fastened to the hoop, as shown in Fig. 3.
These are to hold the wick ball, Fig. 4, so it will hang as shown
in Fig. 5. The wick ball is made by winding wicking around a wire,
having the ends bent into hooks as shown.

The balloon is filled with hot air in a manner similar to that
used with the ordinary cloth balloon. A small trench or fireplace
is made of brick having a chimney over which the mouth of the
paper balloon is placed. Use fuel that will make heat with very
little smoke. Hold the balloon so it will not catch fire from the
flames coming out of the chimney. Have some alcohol ready to pour
on the wick ball, saturating it thoroughly. When the balloon is
well filled carry it away from the fireplace, attach the wick ball
to the cross wires and light it.

In starting the balloon on its flight, take care that it leaves
the ground as nearly upright as possible.
--Contributed by R. E. Staunton.



** A Simple Steamboat Model [216]

The small boat shown in the accompanying sketch may have a length
of 12 to 18 in. and is constructed in the

[Illustration: Sectional View and Completed Boat]

following manner: A small steam boiler, A, is supported by two
braces over an alcohol lamp in the middle of the boat. A small
pipe is fastened to the top of the boiler in such a way that the
open end will be opposite the open end of another pipe, B,
somewhat larger in size. The pipe B opens into the stern of the
boat at C, as shown in Fig. 1. The steam, coming through the small
pipe A, is driven forcibly through the larger pipe B, and carries
with it a certain amount of air out through the opening C into the
water. As the boat is driven forward by this force, the steam
arises to the surface in the form of bubbles. The boat soon
attains considerable speed, leaving a long wake behind.



** To Remove Grease from Machinery  [216]

A good way to remove grease or oil from machinery before painting
is to brush slaked lime and water over the surface, leaving the
solution on over night. After washing, the iron is dried and the
paint will stick to it readily. In removing grease from wood,
common whitewash may be left on for a few hours and then washed
off with warm water, after which the paint will adhere
permanently.



** A Game Played on the Ice  [216]

Two lines are drawn parallel on the ice from 50 to 100 ft. apart
and blocks of wood are placed every 6 ft. apart on these lines.
The player opening the game skates to the line and delivers, in
bowling form, a sliding block similar to the blocks that are
placed on the lines with the exception that it has a handle. The
blocks are about 6 in. wide by 6 in. high and 8 in. long. The
sliding blocks should be at least 1 ft. long and each provided
with a handle. The handle is attached by boring a hole near one
end in the middle of the block and driving in a wood pin. The hole
is bored slanting so as to incline the handle. Two of these blocks
are provided for the reason that when a player bowls one of the
opposing player's blocks over the line he is entitled to another
throw. The side wins that bowls over all of the opposing

[Illustration: Bowling Over the Opponent's Blocks]

players' blocks first. This will prove an interesting and
enjoyable pastime for skaters.



** Making Photo Silhouette Brass Plaques [217]

Secure a brass plate having a smooth surface the right size for
the photograph and cover it with a coat of paraffin. This is done
by heating the paraffin in a vessel hot enough to make the wax run
freely, then pouring the liquid over the entire surface of the
brass.

When the paraffin has cooled sufficiently the outlines of the
photograph must be drawn upon its surface. There are three ways of
doing this: First, the photograph can be traced on tissue paper
and then retraced on the paraffin surface. The exact outlines of
the photograph can be obtained this way without destroying the
print. Second, if you have several copies of the photograph, one
can be utilized by tracing direct to the surface of the paraffin.
In using either of the two methods described, carbon paper must be
placed on the paraffin before the tissue paper or photograph is
laid upon it. Third, cut out the outlines of the photograph and
lay it on the paraffin surface, then trace around the edges with
the point of a needle or sharp point of a knife. The outlines
drawn by the first method are cut through the paraffin in the same
way. The paraffin is carefully removed from the inside of the
lines, leaving the brass surface perfectly clean, as is shown in
Fig. 1.

The exposed part of the plate is now ready to be etched or eaten
away to the right depth with acid. The acid solution is made up of
1-1/2 parts muriatic acid and 2 parts water. The mixture should be
placed in a glass or earthenware

[Illustration: Fig. 1 Waxed Brass Plate]

vessel. If the plate is a small one a saucer will do for the acid
solution. Pour the acid on the plate where the paraffin has been
removed and allow it time to etch. The acid should be removed
every five minutes to examine the etching. If any places show up
where the paraffin has not been entirely removed they must be
cleaned so the acid will eat out the metal. When the acid solution
becomes weak new solution must be added until the proper depth is
secured. Rinse the plate in cold water, stand in a tray and heat
it sufficiently to run off all the paraffin. Polish the plate by
rubbing it with a piece of flannel.

The plaque can be given a real antique finish by painting the
etched part with a dull black paint. Drill a small hole in each of
the four corners, being careful not to dent the metal. The plaque
is backed with a piece of wood 3/4 in. thick, the dimensions of
which should exceed those of the brass plate sufficiently to
harmonize with the size of the plaque. The wood should be painted
black with the same paint used in the plaque. Paint the heads of
four thumb tacks black and use them in fastening the plaque to the
board. The finished silhouette will appear as shown in Fig. 2.
--Contributed by John A. Hellwig, Albany, N. Y.

[Illustration: Fig. 2 Finished Plaque]



** Aligning Automobile Headlights [217]

Automobile headlights should be set to throw the light straight
ahead, not pointed down at the road at an angle.



** Telescope Stand and Holder [218]

With the ordinary small telescope it is very difficult to keep the
line of sight fixed upon any particular object. To meet the
situation I constructed the

[Illustration: Fig. 1   Fig. 2   Made of a Camera Tripod]

device illustrated herewith. A circular piece of wood, B, 6 in. in
diameter, is fastened to a common camera tripod, A, with a set
screw, S. Corner irons, CC, are screwed to the circular piece.
These corner irons are also screwed to, and supported in a
vertical position by the wood standard D, which is 4 in. wide and
of any desired height. To this standard is secured the wood
shield-shaped piece E by the screw G upon which it turns. A
semi-circular slit is cut in the piece G, through which passes the
set screw S. The telescope is secured to the piece G by means of
the pipe straps FF. Rubber bands are put around the telescope to
prevent rubbing at the places where the straps enclose it.

The wood pieces were made of mahogany well rubbed with linseed oil
to give them a finish. The corner irons and set screws or bolts
with thumb-nuts can be purchased at any hardware store. The pipe
straps of different sizes can be obtained from a plumber's or gas
and steam fitter's store. With this device, either a vertical or a
horizontal motion may be secured, and, after bringing the desired
object into the line of sight, the set screws will hold the
telescope in position. Anyone owning a tripod can construct this
device in three or four hours' time at a trifling cost. In Fig. 1
is shown the side view of the holder and stand, and Fig. 2 the
front view.

It may be of interest to those owning telescopes without solar
eyepieces to know that such an eyepiece can be obtained very
cheaply by purchasing a pair of colored eyeglasses with very dark
lenses and metal rims. Break off the frame, leaving the metal rims
and nibs at each end. Place these over the eyepiece of the
telescope and secure in place with rubber bands looped over the
nibs and around the barrel of the instrument.
   --Contributed by R. A. Paine, Richmond, Va.



** How to Make an Electrical Horn [218]

Secure an empty syrup or fruit can, any kind having a smooth flat
bottom will do. If the bottom is not perfectly flat, it will
interfere with the regular tone vibrations, and not produce the
right sound. Remove the label by soaking it in hot water. Take an
ordinary electrical bell and remove the gong, clip off the
striking ball and bend the rod at right angles. Cut a block of
wood 3/4 in. thick, 5 in. wide and 8 in. long for the base. Fasten
the can on it with a piece of sheet brass or

[Illustration: Tin Can and Bell Parts]

tin as shown in the sketch. Mount the bell vibrator on the base,
using a small block of wood to elevate it to the level of the
center of the can, and solder the end of the vibrator rod to the
metal.

Connect two dry cells to the bell vibrator, and adjust the contact
screw until a clear tone is obtained. The rapidly moving armature
of the bell vibrator causes the bottom of the can to vibrate with
it, thus producing sound waves. The pitch of the tone depends on
the thickness of the bottom of the can. This horn, if carefully
adjusted and using two cells of dry battery, will give a soft
pleasant tone that can be heard a block away. If the two
projecting parts of the vibrator are sawed off with a hacksaw, it
can be mounted on the inside of the can. This will make a very
compact electric horn, as only the can is visible. --Contributed
by John Sidelmier, La Salle, Ill.



** Driving a Washing Machine with Motorcycle Power [219]

The halftone illustration shows how 1 rigged up my washing machine
to be driven by the power from my motorcycle. I made a wheel 26
in. in diameter of some 1-in. pine boards, shrunk an iron band on
it for a tire, and bolted it to the wheel on the washing machine.
A long belt the same width as the motorcycle belt was used to
drive the machine. The motorcycle was lined up and the engine
started, then the motorcycle belt thrown off and the long belt run
on, connecting the engine and washing machine wheel. -1. R.
Kidder, Lake Preston, S. D.

[Illustration: Machine Belted to the Motorcycle]



** Home-Made Aquarium [219]

A good aquarium can be made from a large-sized street lamp globe
and a yellow pine block. Usually a lamp globe costs less than an
aquarium globe of the same dimensions. Procure a yellow pine block
3 in. thick and 12 in. square. The more uneven and twisted the
grain the better for the purpose,

[Illustration: Lamp Globe as an Aquarium]

it is then less liable to develop a continuous crack.

Cut out a depression for the base of the globe as shown in Fig. 1.
Pour in aquarium cement and embed the globe in it. Pour more
cement inside of the globe until the cement is level with the top
of the block. Finish with a ring of cement around the outside and
sprinkle with fine sand while the cement is damp. Feet may be
added to the base if desired. The weight of the pine block makes a
very solid and substantial base for the globe and renders it less
liable to be upset.
--Contributed by James R. Kane, Doylestown, Pa



** Protect Your Lathe [219]

Never allow lard oil to harden on a lathe.



** Frame for Displaying Both Sides of Coins [220]

It is quite important for coin collectors to have some convenient
way to

[Illustration: Holding Coins between Glasses]

show both sides of coins without touching or handling them. If the
collection consists of only a few coins, they can be arranged in a
frame as shown in Fig. 1. The frame is made of a heavy card, A,
Fig. 2, the same thickness as the coins, and covered over on each
side with a piece of glass, B. Holes are cut in the card to
receive the coins C. The frame is placed on bearings so it may be
turned over to examine both sides. If there is a large collection
of coins, the frame can be made in the same manner and used as
drawers in a cabinet. The drawers can be taken out and turned
over.
--Contributed by C. Purdy, Ghent, O.



** How to Make Lantern Slides [220]

A great many persons who have magic lanterns do not use them very
much, for after the slides have been shown a few times, they
become uninteresting, and buying new ones or even making them from
photographic negatives is expensive. But by the method described
in the following paragraph anyone can make new and interesting
slides in a few minutes' time and at a very small cost.

Secure a number of glass plates of the size that will fit your
lantern and clean them on both sides. Dissolve a piece of white
rosin in a half-pint of gasoline and flow it over one side of the
plates and allow to dry. Place the dried plate over a picture you
wish to reproduce and draw the outline upon the thin film. A lead
pencil, pen and ink or colored crayons can be used, as the rosin
and gasoline give a surface that can be written upon as easily as
upon paper. When the slide becomes uninteresting it can be cleaned
with a little clear gasoline and used again to make another slide.
A slide can be made in this way in five minutes and an interesting
outline picture in even less time than that.

This solution also makes an ideal retouching varnish for
negatives.
--Contributed by J.E. Noble, Toronto, Canada.



** How to Make a Developing Box [220]

A box for developing 3-1/4 by 4-1/4 -in. plates is shown in detail
in the accompanying sketch. It is made of strips of wood 1/4-in.
thick, cut and grooved, and then glued together as indicated. If
desired, a heavier piece can be placed on the bottom. Coat the
inside of the box with paraffin or wax, melted and applied with a
brush. Allow it to fill all crevices so that the developing box
will be watertight. It will hold 4 oz. of developer. Boxes for
larger plates

[Illustration: Details of the Developing Box]

can be made in the same manner. Use a small wooden clip in taking
the plates out of the box, being careful not to scratch the
sensitive film.
--Contributed by R.J. Smith, Milwaukee, Wis.



** Staining Wood [221]

A very good method of staining close-grained woods is to use
muriatic acid. The acid is put on with a brush like any ordinary
stain. The colors thus obtained are artistic and most beautiful,
and cannot be duplicated by any known pigment. The more coats
applied the darker the color will be. This method of staining has
the advantage of requiring no wiping or rubbing.
--Contributed by August T. Neyer, One Cloud, Cal.



** Sheet-Metal Whisk-Broom Holder [221]

A whisk-broom holder such as is shown in the accompanying picture
may be easily made by the amateur. The tools needed are few: a
pair of tin shears, a metal block of some kind upon which to pound
when riveting, a hammer or mallet, several large nails, and a
stout board upon which to work up the design. A rivet punch is
desirable, though not absolutely necessary.

The material required is a sheet of No. 24 gauge copper or brass
of a size equal to that of the proposed holder, plus a 3/8-in.
border all around, into which to place the screws that are to be
used to hold the metal to the board while pounding it. The design
shown in the picture is 6 by 8 in. at the widest part and has
proven a satisfactory holder for a small broom.

Carefully work out the design desired on a piece of drawing paper,
both outline and decoration, avoiding sharp curves in the outline
because they are hard to follow with the shears when cutting the
metal. If the design is to be of two-part symmetry, like the one
shown, draw one part, then fold on a center line and duplicate
this by inserting double-surfaced carbon paper and tracing the
part already drawn. With this same carbon paper transfer the
design to the metal. Fasten the metal to the board firmly, using
1/2-in. screws placed about 1 in. apart in holes previously
punched in the margin with a nail set or nail.

To flatten the metal preparatory to fastening it to the board,
place a block of wood upon it and pound on this block, never upon
the metal directly,

[Illustration: Completed Holder Brass Fastened to Board-Method of
Riveting]

or the surface will be dented and look bad in the finished piece.

Take the nail, a 10 or 20-penny wire or cut, and file it to a
chisel edge, rounding it just enough to take the sharpness off so
that it will not cut the metal. This tool is used for indenting
the metal so as to bring out the outline of the design on the
surface.

There are several ways of working up the design. The simplest way
is to take the nail and merely "chase" the outlines of holder
design. Remove the screws, cut off the surplus metal and file the
edges until they are smooth. Make a paper pattern for the metal
band that is to hold the broom. Trace around this pattern on the
metal and cut out the shape. Punch rivet holes in holder and band,
also a hole by which to hang the whole upon the wall.

Rivet the band to the holder. Punch the rivet holes with a nail
set and make the holes considerably larger than the diameter of
the rivet, for in flattening the raised edges the holes will
close. Do the riveting on a metal block and keep the head of the
rivet on the back of the holder. Round up the "upset" end of the
riveted part as shown in the picture. Do not bend it over or
flatten it. This rounding is done by pounding around the outer
edge of the rivet end and not flat upon the top as in driving a
nail.

Clean the metal by scrubbing it off with a solution composed of
one-half water and one-half nitric acid. Use a rag tied to a stick
and do not allow the acid to touch either your hands or clothes. A
metal lacquer may next be applied to keep the metal from early
corrosion.



** How to Make a Camp Stool [222]

The stool, as shown in Fig. 1, is made of beech or any suitable
wood

[Illustration: Camp Stool Details]

with a canvas or carpet top. Provide four lengths for the legs,
each 1 in. square and 18-1/2 in. long; two lengths, l-1/8 in.
square and 11 in. long, for the top, and two lengths, 3/4 in.
square, one 8-1/2 and the other 10-1/2 in. long, for the lower
rails.

The legs are shaped at the ends to fit into a 5/8-in. hole bored
in the top pieces as shown in Fig. 2, the distance between the
centers of the holes being 7-5/8 in. in one piece and 9-5/8 in. in
the other. The lower rails are fitted in the same way, using a
1/2-in. hole bored into each leg 2-1/2 in. up from the lower end.

Each pair of legs has a joint for folding and this joint is made
by boring a hole in the middle of each leg, inserting a bolt and
riveting it over washers with a washer placed between the legs as
shown in Fig. 3. The entire length of each part is rounded off for
the sake of neatness as well as lightness.

About 1/2 yd. of 11-in. wide material will be required for the
seat and each end of this is nailed securely on the under side of
the top pieces. The woodwork may be stained and varnished or plain
varnished and the cloth may be made to have a pleasing effect by
stencilling in some neat pattern.



** A Small Home-Made Electric Motor  [222]

The accompanying photographs show the construction of a very
unique electric motor, the parts consisting of the frame from an
old bicycle pedal wrapped with insulated wire to make the armature
and three permanent magnets taken from an old telephone magneto.
The pedal, being ball bearing, rotated with very little friction
and at a surprisingly high rate of speed.

[Illustration: The Motor Complete]

The dust cap on the end of the pedal was removed and a battery
connection, having quite a length of threads, was soldered to it
as shown in the photograph. The flanges were removed from an
ordinary spool and two strips of brass fastened on its
circumference for the commutator. The spool was held in position
by a small binding

[Illustration: Commutator Parts]

post nut. The shape of this nut made a good pulley for a cord
belt.
--Contributed by John Shahan, Attalla, Ala.



** Rocker Blocks on Coaster Sleds [223]

The accompanying sketch shows a coasting sled with rocker blocks
attached on both front and rear runners. The runners and the other
parts of the sled are made in the usual way, but instead of
fastening the rear runners solid to the top board and the front
runners to turn on a solid plane fifth wheel, they are pivoted so
each pair of runners will rock when going over bumps.

The illustration will explain this construction without going into
detail and giving dimensions for a certain size, as these rocker
blocks can be attached to any coaster or toboggan sled. It will be
noticed that the top board may bend as much as it will under the
load without causing the front ends of the rear runners and the

[Illustration: Coaster Sled with Rocker Runners]

rear ends of the front runners gouging into the snow or ice.
--Contributed by W. F. Quackenbush, New York City.



** How to Make a Watch Fob [223]

[Illustration: Watch Fob]

This novelty watch fob is made from felt, using class, college or
lodge colors combined in the making with emblems or initials
colored on the texture. Two pieces of felt, each 1-1/4 in. wide
and 4-1/4 in. long, are cut V-shaped on one end of each piece
about 1 in. in depth, and 3/8 in. in from the other end of one
piece cut a slit 1/2 in. long; the end of the other piece is
folded over, making a lap of about 1 in., and a slit is cut
through the double thickness to match the one cut in the first
piece. The desired emblem, initial, or pennant is stenciled on the
outside of the folded piece with class, college or lodge colors.
The strap is made from a strip of felt 3/16 in. wide and 8-1/4 in.
long; stitched on both edges for appearance. Make a hole with a
punch 1-1/4 in. from one end, and two holes in the other, one
about 1 in. and the other 2-3/4 in. from the end. Purchase a
1/2-in. buckle from a harness maker and you will have all the
parts necessary for the fob. Assemble as shown in the sketch. The
end of the strap having the two holes is put through the slots cut
in the wide pieces and the tongue of the buckle is run through
both holes. The other end is passed through the ring of the watch
and fastened in the buckle as in an ordinary belt. --Contributed
by C. D. Luther. Ironwood. Mich.



** Drill Lubricant [223]

A good lubricant for drilling is made by dissolving 3/4 to 1 lb.
of sal-soda in one pailful of water.



** New Way to Remove a Bottle Stopper [224]

Take a bottle of liquid, something that is carbonated, and with
the aid of a napkin form a pad which is applied

[Illustration: Removing the Stopper]

to the lower end of the bottle. Strike hard with repeated blows
against the solid surface of a wall, as shown in the sketch, and
the cork will be driven out, sometimes with so much force that a
part of the liquid comes with it and deluges the spectators, if
desired by the operator.



** Imitation Fancy Wings on Hinges [224]

The accompanying sketch shows how I overcame the hardware troubles
when I was not able to find ready-made hinges in antique design
for a mission sideboard and buffet. This method allows a wide
range of designs, which

[Illustration: Fancy Hinge Wings]

can be made at home with ordinary tools. The wings are made of
copper or brass and finished in repoussé, or can be tarnished and
the high places burnished with 000 sandpaper or steel wool, then
lacquered with white shellac or banana bronzing liquid.
--Contributed by John H. Schatz, Indianapolis, Ind.



** How to Make a Child's Rolling Toy [224]

Secure a tin can, or a pasteboard box, about 2 in. in diameter and
2 in. or more in height. Punch two holes A, Fig. 1, in the cover
and the bottom, 1/4 in. from the center and opposite each other.
Then cut a curved line from one hole to the other, as shown at B.
A piece of lead, which can be procured from a plumber, is cut in
the shape shown in Fig. 2, the size being 1 by 1-1/8 by 1-1/4 in.
An ordinary rubber band is secured around the neck of the piece of

[Illustration: Rolling Can Toy]

lead, as shown in Fig. 3, allowing the two ends to be free. The
pieces of tin between the holes A, Fig. 1, on both top and bottom,
are turned up as in Fig. 4, and the ends of the bands looped over
them. The flaps are then turned down on the band and the can parts
put together as in Fig. 5. The can may be decorated with brilliant
colored stripes, made of paper strips pasted on the tin. When the
can is rolled away from you, it winds up the rubber band, thus
storing the propelling power which makes it return. --Contributed
by Mack Wilson, Columbus, O.



** How to Make a Portfolio [225]

Secure a piece of Russian modeling calf leather of a size equal to
12 by 16 in. Make a paper pattern of the size indicated in the
accompanying drawing, putting in the design.

The necessary tools consist of a stick with a straight edge and a
tool with an end shaped like that of a nutpick. A nutpick with a
V-shaped point will do if the sharpness is smoothed off by means
of a piece of emery paper, so that it will indent without cutting
the leather. These tools can be bought for this special purpose,
but are not essential for this piece if the nutpick is at hand.
There

[Illustration: Portfolio Design]

will also be needed a level, non-absorbent surface upon which to
lay the leather while working it. A piece of thick glass, metal,
or marble will serve.

Begin work by moistening the leather on the back side with a
sponge or cloth. Moisten as much as you dare and still not have
the moisture show on the face side. Next place the leather on the
glass, face up, and, holding the pattern firmly in place so that
it will not slip--if possible get some one to hold the pattern for
you--place the straight edge on the straight lines and mark out or
indent. After this has been done, mark over the design. A pencil
may be used the first time over.

The pattern is now to be removed and all the lines gone over with
the tool to make them deep and uniform.

The surplus stock around the edges may not be cut off. A neat way
to finish the edges is to punch a series of holes entirely around
through which a thin leather thong may be laced. If it is desired
to "line" the inside, this should be done before the holes are
punched or the lacing done.



** Gear for Model Work [225]

When a gear is needed to drive a small pinion and there is none of
the right size at hand, one can be made in the following manner:
Turn up a wood disk to the proper diameter and 1/4 in. thicker
than the pinion, and cut a flat bottom groove 3/16 in. deep in its
face. The edges should be about 1/8 in. or more thick on each
side. Measure the distance between centers of two adjacent teeth
in the pinion and step this off around the periphery in the bottom
of the groove. Drill holes into the wood on each point stepped off
and insert steel pins made of wire, allowing

[Illustration: Steel Pins in Wood]

the end of each to protrude just far enough to act as a tooth. In
this way a good gear for light work can be quickly and cheaply
constructed.
--Contributed by Henry Schaefer, New York City.



** A Home-Made Vise [226]

While making a box I had some dovetailing to do, and as there was
no

[Illustration: Vise on Bench]

vise on the bench I rigged up a substitute. I secured a board 3/4
in. thick, 3 in. wide and 20 in. long and bored a 1/2-in. hole
through it, 1 in. from each end. The board was then attached to
the bench with two screws passing through washers and the two
holes in the . board into the bench top. The screws should be of a
length suitable to take in the piece to be worked. --Contributed
by A. M. Rice, Syracuse, New York.



** Cardboard Spiral Turned by Heat [226]

A novel attraction for a window display can be made from a piece
of stiff cardboard cut in a spiral as shown in Fig. 1. The
cardboard should be about 7 or 8 in. in diameter. Tie a piece of
string to the center point of the spiral

[Illustration: Spiral Cut from Cardboard]

and fasten it so as to hang over a gas jet, Fig. 2. A small swivel
must be put in the string at the top or near the cardboard, if it
is desired to have the spiral run for any length of time. The
cardboard will spin around rapidly and present quite an
attraction.
--Contributed by Harry Szerlip, Brooklyn, N. Y.



** A Workbench for the Amateur [226]

The accompanying detail drawing shows a design of a portable
workbench suitable for the amateur woodworker. This bench can be
made easily by anyone who has a few sharp tools and a little spare
time. If the stock is purchased from the mill ready planed and cut
to length, much of the hard labor will be saved. Birch or maple
wood makes a very good bench. and the following pieces should be
ordered:

    4 legs, 3 by 3 by 36.
    2 side rails, 3 by 3 by 62-1/2 in.
    2 end rails, 3 by 3 by 20 in.
    1 back board, 1 by 9 by 80 in.
    1 top board, 2 by 12 by 77 in.
    1 top board, 1 by 12 by 77 in.
    2 crosspieces, 1-1/2 by 3 by 24 in.
    1 piece for clamp, 1-1/2 by 6-1/2 by 12 in.
    1 piece for clamp, 1-1/2 by 6-1/2 by 14 in.
    4 guides, 2 by 2 by 18 in.
    1 screw block, 3 by 3 by 6 in.
    1 piece, 1-1/2 by 4-1/2 by 10-1/2 in.


Make the lower frame first. Cut tenons on the rails and mortise
the posts, then fasten them securely together with 3/8 by 5-in.
lag screws as shown. Also fasten the 1-1/2 by 3 by 24-in. pieces
to the tops of the posts with screws. The heads should be
countersunk or else holes bored in the top boards to fit over
them. Fasten the front top board to the crosspieces by lag screws
through from the under side. The screws can be put in from the top
for the 1-in. thick top board.

Fasten the end pieces on with screws, countersinking the heads of
the vise end. Cut the 2-in. square holes in the 1-1/2 by 4-1/2 by
10-in. pieces for the vise slides, and fit it in place for the
side vise. Also cut square holes in the one end piece for the end
vise slides as shown. Now fit up the two clamps. Fasten the slides
to the front pieces with screws. Countersink the heads of the
screws so they will not be in the way of the hands when the vise
is used. The two clamp screws should be about 1-1/2 in. in
diameter. They can be purchased at a hardware store. A block
should be fitted under the crosspiece to hold the nut for the end
vise. After

[Illustration: Detail of the Bench]

you have the slides fitted, put them in place and bore the holes
for the clamp screws.

The back board can now be fastened to the back with screws as
shown in the top view. The bench is now complete, except for a
couple of coats of oil which should be applied to give it a finish
and preserve the wood. The amateur workman, as well as the pattern
maker, will find this a very handy and serviceable bench for his
workshop.

As the amateur workman does not always know just what tools he
will need, a list is given which will answer for a general class
of work. This list can be added to as the workman becomes more
proficient in his line and has need for other tools. Only the long
run. If each tool is kept in a certain place, it can be easily
found when wanted.

    1 bench plane or jointer;
    1 jack plane or smoother;
    1 cross cut saw, 24 in.;
    1 rip saw, 24 in.;
    1 claw hammer;
    1 set gimlets;
    1 brace and set of bits;
    2 screwdrivers, 3 and 6 in.;
    1 countersink;
    1 compass saw;
    1 set chisels;
    1 wood scraper;
    1 monkey wrench;
    1 2-ft. rule;
    1 marking gauge;
    1 pair pliers;
    1 nail set;
    1 pair dividers;
    1 pocket level;
    1 6-in. try square;
    1 oilstone;
    No.1, 2 and 00 sandpaper.

[Illustration: Workbench Complete]



** Repairing a Worn Knife Blade [228]

When the blade of a favorite pocket knife, after constant use,
becomes like A, Fig. 1, it is more dangerous than

[Illustration: The Blade Is Cut Down]

useful. To cut down the already worn blade would leave only a
stump, but if the blade is fastened in a vise and the point B
filed off until it is like C, Fig. 2, the projecting point A, Fig.
1, will sink into the handle as shown at D, Fig. 3, and the knife
will be given a new lease of usefulness. -
--Contributed by James M. Kane, Doylestown, Pa.



** How to Make a Leather Spectacle Case [228]

The spectacle case shown in the accompanying illustration may be
made of either calf or cow skin. The calf skin, being softer, will
be easier to work, but will not make as rigid a case as the cow
skin. If calf skin is to be used, secure a piece of modeling calf.
The extreme width of the case is 2-3/8 in. and the length 6-5/8
in. Two pieces will be required of this size. Put on the design
before the two parts are sewed together. First draw the design on
paper, then prepare the leather. Place the leather on a small
non-absorbent surface, such as copper or brass, and moisten the
back side with as much water as it will take and still not show on
the face side. Turn the leather, lay the design on the face, and
hold it in place while both the outline and decoration are traced
on the surface with a pencil or some tool that will make a sharp
line without tearing the paper.

After the outlines are traced, go over the indentations a second
time so as to make them sharp and distinct. There are special
modeling tools that can be purchased for this purpose, but a
V-shaped nut pick, if smoothed with emery paper so that it will
not cut the leather, will do just as well.

Take a stippling tool--if no such tool is at hand, a cup-pointed
nail set will do--and stamp the background. It is intended that
the full design shall be placed on the back and the same design
placed on the front as far as the material will allow. Be careful
in stamping not to pound so hard as to cut the leather. A little
rubbing on the point with emery will take off the sharpness always
found on a new tool.

Having prepared the two sides, they may be placed together and
sewed around the edges.

If cow hide is preferred, the same

[Illustration: Two Designs of Cases]

method of treatment is used, but a form will need to be made and
placed inside the case while the leather is drying to give it the
right shape. The form can be made of a stick of wood.



** Waterproofing a Wall [229]

The best way to make a tinted wall waterproof is to first use a
material composed of cement properly tinted and with no glue in
it--one that will not require a glue size on the wall. After this
coating of cement is applied directly to the plaster, cover it
completely with water enamel and, when dry, give the surface a
thorough coating of varnish. This will make a perfectly impervious
covering, which steam, water or heat will not affect.
--Contributed by Julia A. White, New York City.



**Polishing Flat Surfaces [229]

[Illustration: Polisher]

The work of finishing a number of brass castings with flat sides
was accomplished on an ordinary polishing wheel, from which the
first few layers of cloth were removed and replaced with emery
cloth. The emery surface of the cloth was placed outward and
trimmed to the same diameter as the wheel. This made a sanding and
polishing wheel in one.
--Contributed by Chester L. Cobb, Portland, Maine.



** Rubber Tip for Chair Legs [229]

[Illustration: Rubber Tips]

An inexpensive method of preventing a chair from scratching the
floor is to bore a hole of the proper size in the bottom end of
each chair leg and then procure four rubber stoppers of uniform
size and press them into place.

This cushion of rubber eliminates vibrations, and they will not
slip nor mar the finest surface upon which they rest.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Adjusting a Plumb-Bob Line [229]

[Illustration: Line Adjustment]

When plumbing a piece of work, if there is no help at hand to hold
the overhead line, it is common practice to fasten the plumb line
to a nail or other suitable projection. On coming down to the
lower floor it is often found that the bob has been secured either
too high or too low. When fastening the line give it plenty of
slack and when the lower floor is reached make a double loop in
the line, as shown in the sketch. Tightening up on the parts AA
will bind the loop bight B, and an adjustable friction-held loop,
C, will be had for adjusting the bob accurately either up or down.
--Contributed by Chas. Herrman, New York City.



** Drier for Footwear [229]

A drier for footwear can be readily made by a tinner, or anyone
that can shape tin and solder. The drier consists of a pipe of
sufficient length to enter the longest boot leg. Its top is bent
at right angles and the other end is riveted to a base, an
inverted stewpan, for instance, in whose bottom a few perforations
have been made to let air in. The boot or stocking to be dried is
placed over the pipe and the whole set on a heated surface. The
heat will cause a rapid circulation of air which will dry the
article quickly.
--Contributed by Wm. Roberts, Cambridge, Mass.

[Illustration: Show Drier]



** Repairing A Roller Shade [229]

A very satisfactory repair can be made by using a good
photographic paste to fasten a torn window shade to its roller.



** A Shot Scoop [230]

In the ammunition department of our hardware store the shot was
kept in regular square bins and dished out

[Illustration: A Small Square Scoop Made of Tin for Dipping Up
Shot Stored in a Square Bin]

with a round-bottom scoop. This was very difficult, especially
when the bottom of the bin was nearly reached, as the round scoop
would roll over them and only pick up a few at a time. To overcome
this difficulty I constructed a square-shaped scoop that gave
entire satisfaction. The scoop can be used for other purposes as
well.

A thick piece of tin, 6-1/4 by 9-3/4 in., was marked out as shown,
the pattern being cut on the full lines and bent on the dotted
ones. The strip for the handle was riveted to the end of the
scoop.
--Contributed by Geo. B. Wright, Middletown, Conn.



** Removing Grease Stains from the Leaves of a Book [230]

Happening to get a grease spot on a page of a valuable book, I
found a way to remove it without injury to the paper, which has
been tried out several times with success.

Heat an iron and hold it as near as possible to the stain without
discoloring the paper, and the grease will disappear. If any
traces of the grease are left, apply powdered calcined magnesia.
Bone, well calcined and powdered, and plaster of Paris are also
excellent absorbents of grease.

A beautifully bound book, and quite new, had oil from a lamp
spilled over it. There was no quicklime to be had, so some bones
were quickly calcined, pulverized and applied. The next morning
there was no trace of oil, but only an odor which soon vanished.
--Contributed by Paul Keller, Indianapolis, Ind.



** Tightening Cane in Furniture [230]

Split cane, used as part of furniture, such as chair seats, often
becomes loose and the threads of cane pull out. This can be
prevented by sponging with hot water, or by applying steaming
cloths to the cane. This process also tightens the shreds of cane
and does not injure ordinary furniture. If the article is highly
polished, care should be taken to prevent the hot water from
coming in contact with anything but the cane.



** Cleaner for a Stovepipe [230]

A long horizontal pipe for a stove soon fills with soot and must
be cleaned. The usual method is to beat the pipe after taking it
down to be cleaned, but a much better device for the purpose is
shown in the sketch.

A scrub brush is procured and cut in two, the parts being hinged
to a crosspiece fastened to a long broom handle. The brushes are
pressed outward

[Illustration: Stovepipe Brush]

against the inside surfaces of the pipe with a wire and spring, as
shown.
--Contributed by C. L. Herbert, Chicago, Illinois.



** Mounting Photo Prints on Glass [231]

Photograph prints can be mounted on glass with an adhesive made by
soaking 1 oz. of sheet gelatine in cold water to saturation, then
dissolving in 3-1/2 oz. of boiling water. Let the solution cool to
about 110 deg. F., then immerse the print in it and squeegee, face
down, on a clear piece of glass. When dry, take a damp cloth or
soft sponge and wipe off any surplus gelatine on the glass.



** Dropping Coins in a Glass Full of Water [231]

Take a glass and fill it to the brim with water, taking care that
the surface of the water is raised a little above the edge of the
glass, but not running over. Place a number of nickels or dimes on
the table near the glass and ask your spectators how many coins
can be put into the water without making it overflow. No doubt the
reply will be that the water will run over before two coins are
dropped in. But it is possible to put in ten or twelve of them.
With a great deal of care the coins may be made to fall without
disturbing the water, the surface of which will become more and
more convex before the water overflows.

[Illustration: Dropping Coins]



** Hollow-Grinding Ice Skates [231]

The accompanying sketch illustrates a practical method of clamping
ice skates to hold them for grinding the small arc of a circle so
much desired.

The U-shaped clamps are made of 3/4-in. soft steel with the
opening 6 in. deep and 5 in. high and are bolted to a block of
wood, 2 in. thick, 6 in. wide and 12 in. long. The skate runner is
adjusted to the proper height by 1/2-in.. set and thumbscrews. The
block

[Illustration: Skate Runner Fastened in Clamp]

of wood holding the clamp and skate can be pushed along on the
emery-wheel table in front of the revolving wheel.

If properly adjusted, a slight concave or hollow can be made full
length of the runner, true and uniform which will hold on the ice
sideways and not retard the forward movement.
--Contributed by Geo. A. Howe, Tarrytown, New York.



** How to Make a Bicycle Coasting Sled [231]

The accompanying drawing and sketch illustrate a new type of
coasting sled built on the bicycle principle. This coaster is
simple and easy to make, says Scientific American. It is
constructed of a good quality of pine. The pieces marked S are
single, and should be about 1 by 1-1/2 in.; the pieces

[Illustration: Has the Lines of a Bicycle]

marked D are double or in duplicate, and should be 1/2 by 1-1/2
in.

[Illustration: Coasting]

The runners are shod with iron and are pivoted to the uprights as
shown, double pieces being secured to the uprights to make a fork.
The seat is a board, to the underside of which is a block, which
drops down between the two top slats and is secured with a pin. A
footrest is provided consisting of a short crosspiece secured to
the front of the frame and resting on the two lower slats. The
frame and front fork are hinged together with four short eyebolts,
E, with a short bolt through each pair as shown.



** Spelling Names with Photo Letters [232]

There are, no doubt, many amateur photographers who make only
occasional trips afield or through the more traveled thoroughfares
with their cameras during the winter months. Each one is generally
interested in working up the negatives that he or she made during
the summer or on that last vacation into souvenir post cards,
albums and the like, for sending to friends. Illustrated herewith
is something different from the album or photographic calendar.
The letters forming part of the word POPULAR are good examples of
this work.

The masks which outline the letters are cut from the black paper
in which plates come packed. Their size depends on the plate used.
A sharp knife, a smooth board and a straightedge are all the tools
needed, says Camera Craft. If the letters are all cut the same
height, they will look remarkably uniform, even if one is not
skilled in the work of forming them all in accordance with the
rules. Be sure to have the prints a little larger than the letters
to insure a sufficient margin in trimming, so as to have a white
margin around the finished letters. The best method is to use a
good pair of scissors or a sharp knife.

Many combinations can be made of these letter pictures to spell
out the recipient's name or the season's greeting. During the
holidays the letters may be made from winter scenes to spell "A
Merry Christmas" or "A Happy New Year." An Easter greeting may
have more spring-like subjects and a birthday remembrance a
fitting month. The prints are no more difficult to make than the
ordinary kind. In cutting out an 0, for example, do not forget to
cut out a piece to correspond to the center. This piece can be

[Illustration: Letters Made from photographs]

placed on the printing paper after the outline mask has been laid
down, using care to get it in the right position, and closing the
frame carefully so that the small piece will not be disturbed. The
letters should be of the kind to give as large an area of surface
to have as much of the picture show as possible. What the printer
calls black face letters are the most suitable.

By cutting the letters out of black paper in a solid form, and
using these as a mask for a second printing after printing the
full size of the negatives, these letter pictures can be made with
a black border. So made, they can be trimmed to a uniform black
line all around; and, mounted on a white card and photographed
down to post card size, the greeting so spelled out makes a most
unique souvenir. Another application of the letters in copying is
to paste them on a white card as before, trim the card even with
the bottoms of the letters, stand the strip of card on a mirror
laid flat on a table, and then photograph both the letters and
their reflections so as to nicely fill a post card. Still another
suggestion is to cut out the letters, after, pasting the prints on
some thin card, and then arrange them in the desired order to
spell out the name or greeting, but with flowers interspersed and
forming a background, photographing them down to the desired size.
A third means of securing a novel effect by photographing down an
arrangement of the letters is to have them cut out in stiff form
as in the last method; mount them on short pieces of corks, in
turn fastened to a white card forming the background. So arranged,
the letters will stand out from the card about 1/2 in. If they are
now placed in a light falling from the side and slightly in front,
each letter will cast a shadow upon the background, and in the
finished print the letters will look as if suspended in the air in
front of the surface of the card.



** Holding a Loose Screw [233]

A piece of sheet lead put on each side of a screw will fill up and
hold the threads in a too large hole.

A Checker Board Puzzle [233]

Place eight checker men upon the checker board as shown in the
first row in the sketch. The puzzle is to get

[Illustration: Placing the Checkers]

them in four piles of two men each without omitting to jump over
two checker men every time a move is made.

The first move is to jump 5 over 4 and 3 on 2 which is shown in
the second row, then jump 3 over 4 and 6 on 7 and the positions
will appear as shown in the third row; jump 1 over 2 and 5 on 4 to
get the men placed like the fourth row and the last move is to
jump 8 over 3 and 7 on 6 which will make the four piles of two men
each as shown in the fifth row.
--Contributed by I. G. Bayley, Cape May Point, N.J.



** A Home-Made Rabbit Trap [233]

[Illustration: Rabbit in the Trap]

A good serviceable rabbit trap can be made by sinking a common dry
goods box in the ground to within 6 in. of its top. A hole 6 or 7
in. square is cut in each end level with the earth's surface and
boxes 18 in. long that will just fit are set in, hung on pivots,
with the longest end outside, so they will lie horizontal. A
rabbit may now look through the two tubes, says the American
Thresherman. The bait is hung on a string from the top of the
large box so that it may be seen and smelled from the outside. The
rabbit naturally goes into the holes and in this trap there is
nothing to awaken his suspicion. He smells the bait, squeezes
along past the center of the tube, when it tilts down and the game
is shot into the pit, the tube righting itself at once for another
catch. The top and sides of the large box may be covered with
leaves, snow or anything to hide it. A door placed in the top will
enable the trapper to take out the animals. By placing a little
hay or other food in the bottom of the box the trap need not be
visited oftener than once a week.



** Old-Time Magic - Changing a Button into a Coin [234]

Place a button in the palm of the left hand, then place a coin
between the second and third fingers of the right hand. Keep the
right hand faced down and the left hand faced up, so as to conceal
the coin and expose the button. With a quick motion bring the left
hand under the right, stop quick and

[Illustration: Making the Change]

the button will go up the right-hand coat sleeve. Press the hands
together, allowing the coin to drop into the left hand, then
expose again, or rub the hands a little before doing so, saying
that you are rubbing a button into a coin.
--Contributed by L. E. Parker, Pocatello, Idaho.



** Buttonhole Trick [234]

This trick is performed with a small stick having a loop attached
that is too small for the stick to pass through. Spread out the
string and place it each side of the buttonhole, then draw the
cloth around the hole through the string until it is far enough to
pass the stick through the hole. Pull back the cloth and you have
the string looped in

[Illustration: Buttonhole Trick]

the hole with a hitch the same as if the stick had been passed
through the string.

The stick may be removed by pulling up the loop as if you were
passing the stick through it, putting the stick in the hole and
leaving the string on the outside, then spread the string, pulling
up the cloth and passing the stick through the hole as before.
--Contributed by Charles Graham, Pawtucket, Rhode Island.



** How to Remove Paper from Stamps [234]

Old stamps as they are purchased usually have a part of the
envelope from which they are taken sticking to them and in
removing this paper many valuable stamps are torn or ruined. Place
all the stamps that are stuck to pieces of envelopes in hot water
and in a short time they can be separated without injury. Dry the
stamps between two white blotters. Stamps removed in this way will
have a much better appearance when placed in an album.
--Contributed by L. Szerlip, Brooklyn, N. Y.



** Imitation Arms and Armor PART I [235]

Genuine antique swords and armor, as used by the knights and
soldiers in the days of old, are very expensive and at the present
time practically impossible to obtain. The accompanying
illustration shows four designs of swords that anyone can make,
and if carefully made, they will look very much like the genuine
article.

The drawings are so plain that the amateur armorer should have
very little difficulty, if any, in building up his work from the
illustrations, whether he requires a single sword only, or a
complete suit of armor, full size.

The pieces. or designs in this article are from authentic sources,
says the English Mechanic, so that where names are given the
amateur can so label them, and will thereby greatly add to their
interest and value.

An executioners' sword of the fifteenth century is shown in Fig.
1. The blade should be about 27 in. long with a handle of
sufficient length to be grasped by both hands. The width of the
blade near the handle is about 2-1/2 in., tapering down to 1-1/2
in. near the point end. Several ridges are cut around the handle
to permit a firm grip. The cross guard is flat and about 1 in. in
width.

Mark out the shape and size of the blade on a piece of wood 1/8
in. thick, using a straightedge and a pencil, and allowing a few
inches more in length on which to fasten the handle. Cut out the
wood with a scroll saw or a keyhole saw, trim the edges down thin
and smooth both surfaces with fine sandpaper. The end for the
handle is cut about 1 in. wide and 2 in. long. The cross guard is
cut out and a hole made in the center through which to pass the
handle end of the blade. The handle is next made, and if the
amateur does not possess a lathe on which to turn the shape of the
handle, the ridges around the wood may be imitated by gluing and
tacking on pieces of small rope. The handle is then mortised to
receive the 1 by 2-in. end of the blade. The cross guard is now
glued and placed

[Illustration: Swords; Fig. 1, Fig. 2, Fig. 3, Fig. 4]

on the blade, then the hole in the handle is well glued with glue
that is not too thick and quite hot. The blade with the cross
guard is inserted in the handle and allowed to set. When the glue
is thoroughly dry, remove the surplus with a sharp knife and paint
the handle with brown, dark red, or green oil paint. The blade is
covered with tinfoil to give it the appearance of steel. Secure
some pieces of tinfoil and cut one strip 1/2 in. wider than the
blade and the other 1/4 in. narrower. Quickly paint the blade well
with thin glue on one side., then lay evenly and press on the
narrow strip of tinfoil. Glue the other side of the blade, put on
the wider strip of tinfoil and glue the overlapping edge and press
it around and on the surface of the narrow strip. The cross guard
must be covered with tinfoil in the same manner as the blade. When
the whole is quite dry, wipe the blade with light strokes up and
down several times, using a soft and dry piece of cloth. The sword
is then ready to hang in its chosen place as a decoration, not for
use only in cases of tableaux, for which this article will be
especially useful to those who are arranging living pictures
wherein swords and armor are part of the paraphernalia.

A Chinese scimitar is shown in Fig. 2. The handle of this sword is
oval and covered with plaited cord. In making this scimitar,
follow the directions as for Fig. 1, except that the handle has to
be covered with a round black cord. If it is found difficult to
plait the cord on the handle as in the illustration, wind it
around in a continuous line closely together, and finish by
fastening with a little glue and a small tack driven through the
cord into the handle. The pommel is a circular piece of wood, 1/8
in. thick and 5 in. in diameter. The length of the handle,
allowing for a good hold with both hands, should be about 9 in.,
the length of the blade 28 in., the width near the pommel 1-1/2
in. and 3 in. in the widest part at the lower end. The sharp or
cutting edge is only on the short side, the other is flat or
half-round.

A Turkish sabre of ancient manufacture from Constantinople is
shown in Fig. 3. The handle is painted a dull creamy white in
imitation of ivory. The enamel paint sold in small tins will
answer well for this purpose. The cross guard and blade are
covered as described in Fig. 1. The sharp edge is on the longer
curved side, the other is flat or half-round.

A two-handed sword used in the 14th and 15th centuries is shown in
Fig. 4. This sword is about 68 in. long, has a cross guard and
blade of steel with a round wood handle painted black. The ball or
pommel on top of the handle is steel. Both edges of the blade are
sharp. This sword is made in wood the same as described for Fig.
1.



** A Dovetail Joint Puzzle [236]

A simple but very ingenious example in joinery is illustrated. In
the finished piece, Fig. 1, the dovetail appears on each side of
the square stick of

[Illustration: How the Joint Is Cut]

wood, the illustration, of course, shows only two sides, the other
two are identical. The joint is separable and each part is solid
and of one piece. In making, take two pieces of wood, preferably
of contrasting colors, such as cherry and walnut or mahogany and
boxwood, about 1-1/2 in. square and of any length desired. Cut the
dovetail on one end of each stick as shown in Fig. 2, drive
together and then plane off the triangular corners marked A. The
end of each piece after the dovetails are cut appear as shown in
Fig. 3, the lines marking the path of the dovetail through the
stick.



** Radiator Water [236]

Pure rain water is the best to use in a cooling system of an
automobile engine, as it is free from the mineral substances which
are deposited in the radiator, piping and jackets by hard water.



** Springboard for Swimmers [237]

A good springboard adds much to the fun of swimming. The boards
are generally made so that the plank will bend, being dressed down
thin at one end and fastened. The thinness of the plank, or an
insecure fastening, causes many a plank to snap in two or come
loose from its fastenings in a short time.

The accompanying sketch shows the method of constructing a
springboard that does not depend upon the bending of the wood for
its spring. It is made of a plank, 2 in. thick and from 14 to 16
ft. long, one end of which is secured with a hinge arrangement
having a U-shaped rod whose ends are held with nuts. On each edge
of the board, at the lower end, are fastened two pieces of strap
iron, each about 1 ft. long and with the lower ends drilled to fit
the horizontal of the U-shaped rod.

Secure a pair of light buggy springs from a discarded rig and
attach them to the ends of a square bar of iron having a length
equal to the width of the plank. Fasten this to the plank with
bolts, as shown in the sketch. Should the springs be too high they
can be moved forward.
--Contributed by John Blake, Franklin, Mass.

[Illustration: Buggy Springs Used beneath the Board]



** Taking Button from a Child's Nostril [237]

A three-year-old child snuffed a button up its nostril and the
mother, in an attempt to remove it, had caused the button to be
pushed farther up the channel. Doctors probed for the button
without success. The distracted mother happened to think of snuff,
and, as there was some at hand, took a pinch of snuff between the
thumb and forefinger and held it close to the child's nose. The
violent sneezing caused the button to be blown out. Such an
accident may come under the observation of any parent, and if so,
this method can be used to relieve the child when medical
assistance is not at hand.
--Contributed by Katharine D. Morse, Syracuse, N. Y.



** Brass Frame in Repoussé  [237]

Punches can be purchased, as can the pitch bed or block. Both can
be made easily, however. Several punches of different sizes and
shapes will be needed. A piece of mild steel, about 3/8 in.
square, can be easily worked into tools shaped as desired. A cold
chisel will be needed to cut the metal to length; a file to reduce
the ends to shape, and a piece of emery paper to smooth and polish
the end of the tool so that it will not scar the metal.

A small metal box must be secured to hold the pitch. The
illustration shows an iron receptacle. The pitch is prepared by
heating the following materials in these proportions: pitch, 5
lb.; plaster of Paris, 5 lb.; tallow, 1/2

[Illustration: Design for the Frame]

lb. To put it in another way, use pitch and plaster in equal parts
with 1/10 part tallow. See that the pitch and plaster are dry so
that the moisture will not cause the pitch to boil over. Keep
stirring the mass so that it never boils. Melt the pitch first and
add the plaster by degrees.

For a piece of repoussé such as the frame shown, secure a piece of
brass of about No. 18 gauge. With carbon paper trace the design on
the brass. Place the metal on the pitch bed and work over the
outline of the design. Use the chisel-edged tool and try to make
the lines continuous. When this has been done, heat the pitch
slightly

[Illustration: Working Out The Design]

and place the metal, design down, on the pitch, and with the
raising punches work up the shape as desired after the pitch has
hardened. When the desired form has been obtained, turn the metal
over and "touch up" any places improperly raised. The metal will
probably be warped somewhat. To remedy this, place a board on the
metal and pound until the metal assumes a flat shape again. Next
drill a hole in the center waste and saw out for the opening,
using a small metal saw. Trim up the edges and file them smooth.
Clean the metal thoroughly, using powdered pumice with lye. Cotton
batting fastened to the end of a stick will make a good brush.
Upon the cleansed metal put a lacquer to prevent tarnishing. Metal
clips may be soldered to the back to hold the picture in place and
also a metal strip to hold the frame upright. These should be
placed before the metal is lacquered.



** Finding the Horsepower of Small Motors [238]

A small motor often excites curiosity as to its true horsepower,
or fraction of a horsepower. Guesses in this direction vary
remarkably for the same motor or engine. It is comparatively easy
to determine the horsepower put out by almost any machine by the
following method which is intended for small battery motors and
small steam engines.

Before giving the description, it may be well to know what
horsepower means. Horsepower is the rate of work and a unit is
equal to 33,000 ft. lb. per minute, or 550 ft. lb. per second.
That is lifting 33,000 lb. 1 ft. in one minute or 550 lb. 1 ft. in
one second. This may be applied to the problem of finding the
horsepower of a motor by fastening a piece of twine about 25 ft.
long to the shaft of the engine or motor to be tested in such a
way that when the shaft revolves it will wind up the string
similar to a windlass. Place the motor in such a position that the
twine will hang freely without touching anything: out of a high
window will do. Fasten a weight to the other end of the line as
heavy as the motor or engine can lift and still run. It must weigh
enough to slow the power down a little, but not to stop it. Mark
the position of the weight and start the motor, at the same time
accurately measuring time in minutes and seconds it takes to lift
the weight from the lowest point to the highest. Next measure
accurately the distance in feet covered by the weight in its
ascent and obtain the correct weight in pounds of the weight.

Multiply the weight by the distance covered and divide the result
by the number of minutes or fraction of a minute obtained and
divide this last result by 33,000 and the quotient will be the
horsepower of the motor or engine.

Perhaps an illustration will make this solution much plainer.
Suppose the motor will lift a weight of 1 lb. and still revolve,
30 ft. in 10 seconds or 1/6 of a minute. Multiplying 1 by 30 we
get 30, which divided by 1/6 gives 180. This in turn divided by
33,000 equals in round numbers 1/200 part of a horsepower.
--Contributed by Harold H. Cutter.



** Illusion for Window Attraction [239]

Gold fish and canary birds, living together in what seems like one
receptacle, make an unusual show window attraction. Secure two
glass vessels having straight sides of the same height, one 18 in.
in diameter (Fig. 1) and the other 12 in. in diameter (Fig. 2).
The smaller is placed within the larger, the bottoms being covered
with moss and aquarium decorations which can be purchased at a
bird store. Fill the 3-in. space between the vessels with water.
Cut a piece of galvanized screen into circular form to cover the
larger vessel, and hang a bird swing, A, Fig. 3, in the center.
Place the screen on top of the vessels so that the swing will hang
in the center of the inner vessel. A weight--a box filled with
sand will do--should be placed on top of the screen, over the
smaller vessel, to keep it from floating. Moss should be put over
the top of the screen so that the two separate vessels can not be
seen.

[Illustration: 18 in. Diameter; 12 in. Diameter]

[Illustration: Birds and Fish Apparently Together]

Place the birds in the inner vessel and the fish in the water. The
effect is surprising. To complete the effect and aid the illusion
the vessels can be set in a box lined with black velvet, or on a
pedestal.
--Contributed by J. F. Campbell, Somerville, Mass.



** Cleaner for White Shoes [239]

Finely ground whiting mixed with water to the consistency of paste
makes a very good coating for white shoes. A brush can be used in
applying the mixture which will dry in a few minutes. It is best
to mix only as much paste as required for immediate use.
--Contributed . by L. Szerlip, Brooklyn, N. Y.



** Crossing Belt Laces [239]

Belt laces should never cross on the side next to the pulley as
they will cut themselves in two.



** How to Make a Candlestick Holder [240]

A candlestick of very simple construction and design can be made
as follows: Secure a piece of brass or

[Illustration: Candle Holder Complete]

copper of No. 23 gauge of a size sufficient to make the pieces
detailed in the accompanying sketch. A riveting hammer and a pair
of pliers will be needed, also a pair of tin shears and a piece of
metal upon which to rivet.

Cut out a piece of metal for the base to a size of  5-1/2 by 5-1/2
in. Trim the sharp corners off slightly. Draw a pencil line all
around the margin and 5/8 in. away from the edge. With the pliers
shape the sides as shown in the illustration.

Next lay out the holding cup according to the plan of development
shown, and cut out the shape with the shears. Polish both of these
pieces, using any of the common metal polishes. Rivet the cup to
the base, and then, with the pliers, shape the sides as shown in
the photograph. The manner of making and fastening the handle is
clearly illustrated. Use a file to smooth all the cut edges so
that they will not injure the hands.

In riveting, care should be taken to round up the heads of the
rivets nicely as a good mechanic would. Do not be content merely
to bend them over. This rounding is easily accomplished by
striking around the rivets' outer circumference, keeping the
center high.

A good lacquer should be applied after the parts have been
properly cleaned and polished, to keep the metal from tarnishing.

[Illustration: Details of Candle Holder]



** A Home-Made Duplicator [240]

The usual gelatine pad, which is the principal part of the average
hectograph or duplicator, is, as a rule, unsatisfactory, as it is
apt to sour and mold in the summer and freeze in the winter,
which, with other defects, often render it useless after a few
months service.

A compound that is almost indestructible is the preparation sold
at art stores as modeling clay. This clay is as easily worked as a
putty and is spread into the tray, which may be of wood or tin,
and the surface leveled by pounding with a mallet or hammer, then
by drawing a straightedge over it.

The surface of the pad is now saturated with pure glycerine. This
is poured upon the surface after it is slightly warmed, covering
the same and then laying a cloth over the pad and allowing it to
stand long enough for the clay to absorb the glycerine, after
which it is ready for use.

The original copy is written with a copying pencil or typewritten
through a hectograph ribbon. A sheet of newspaper is laid upon the
pad and a round stick or pencil is passed over it to make the
surface level and smooth. Remove the newspaper and place the
original copy face down on the leveled surface and smooth it out
in the same way so that every part touches the pad. Remove the
copy in about five minutes and place the clean sheets of paper one
after another on the surface and remove them. From 50 to 75 copies
of the original can be made in a short time.

This compound is impervious to water, so the negative print is
removed by simply washing with a damp sponge, the same as removing
writing from a slate. This makes it possible to place another
original on the pad immediately without waiting for the ink to
vanish by chemical action as in the original hectograph.

The action of the weather has no effect upon this compound and it
is proof against accident, for the tray may be dropped and the pad
dented or cut into pieces, and the clay can be pressed back and
leveled. The only caution is to keep it covered with a cloth
saturated in glycerine while not in use.
--Contributed by A. A. Houghton, Northville, Mich.



** Paper-Clip Bookmark [241]

The combination of a paper clip and a calling card makes a good
bookmark.

[Illustration: Bookmark]

The clip and card can be kept together by piercing the card and
bending the ends of the wire to stick through the holes. The clip
is attached to a page as shown in the sketch.
--Contributed by Thos. DeLoof, Grand Rapids, Mich.



** Aerating Water in a Small Tank [241]

A simple way of producing air pressure sufficient to aerate water
is by the use of a siphon as shown in Fig. 1. The siphon is made
of glass tubes, the longer pieces being bent on one end as shown.
The air receiver and regulating device are attached to the top end
of the lower tube, as shown in Fig. 2. The receiver or air inlet
is the most important part. It is made of a glass tube, 3/4 in. in
diameter and 5 in. long. A hole is filed or blown through one side
of the glass for the admission of air. The ends of the smaller
glass

[Illustration: FIG.1  FIG.2  Forcing Air Through Water]

tubes are passed through corks having a diameter to fit the ends
of this larger tube. The ends of these tubes should be so adjusted
that the continuous drops of water from the upper will fall into
the tube below. The succession of air bubbles thus imprisoned are
driven down the tube and into the tank below.

The regulator is placed in the tube or siphon above the air
receiver. Its purpose is to retard the flow of water from the
siphon above and make it drop rapidly. It consists of a rubber
connecting tube with two flat pieces of wood clamped over the
center and adjusted with screws. The apparatus is started by
clamping the rubber tube tightly and then exhausting the air in
the siphon tube, then placing the end in the upper reservoir and
releasing the clamp until the water begins to drop. If the
reservoir is kept filled from the tank, the device will work for
an indefinite time.
--Contributed by John T. Dunlop, Shettleston, Scotland.



** Imitation Arms and Armor-Part II [242]

Imitation swords, stilettos and battle-axes, put up as ornaments,
will look well if they are arranged on a shield which is hung high
up on a wall of a room or hall, says the English

[Illustration: FIG 1; FIG 2; FIG 3; Three Fifteenth Century
Swords]

Mechanic, London. The following described arms are authentic
designs of the original articles. A German sword of the fifteenth
century is shown in Fig. 1. This sword is 4 ft. long with the
crossguard and blade of steel. The imitation sword is made of wood
and covered with tinfoil to produce the steel color. The shape of
the sword is marked out on a piece of wood that is about 1/8 in.
thick with the aid of a straightedge and pencil, allowing a little
extra length on which to fasten the handle. Cut the sword out with
a saw and make both edges thin like a knife blade and smooth up
with sandpaper. The extra length for the handle is cut about 1 in.
in width and 2 in. long. The handle is next carved and a mortise
cut in one end to receive the handle end of the blade. As the
handle is to represent copper, the ornamentations can be built up
of wire, string, small rope and round-headed nails, the whole
finally having a thin coat of glue worked over it with a stiff
bristle brush and finished with bronze paint.

The crossbar is flat and about 1 in. in width. Cut this out of a
piece of wood and make a center hole to fit over the extra length
on the blade, glue and put it in place. Fill the hole in the
handle with glue and put it on the blade. When the glue is
thoroughly dry, remove all the surplus with a sharp knife. Sheets
of tinfoil are secured for covering the blade. Cut two strips of
tinfoil, one about 1/2 in. wider than the blade and the other 1/4
in. narrower. Quickly cover one side of the blade with a thin coat
of glue and evenly lay on and press down the narrow strip of
tinfoil. Stick the wider strip on the other side in the same way,
allowing equal margin of tinfoil to overlap the edges of the
blade. Glue the overlapping edges and press them around on the
surface of the narrow strip. The crossguard must be covered in the
same manner as the blade. When the whole is quite dry, wipe the
blade up and down several times with light strokes using a soft
rag.

The sword shown in Fig. 2 is a two-handed Swiss sword about 4 ft.
in length, sharp on both edges with a handle of dark wood around
which is wound spirally a heavy piece of brass or copper wire and
held in place with round-headed brass nails. The blade and
crossbar are in imitation steel. The projecting ornament in the
center of the crossguard may be cut from heavy pasteboard and bent
into shape, then glued on the blade as shown.

In Fig. 3 is shown a claymore, or Scottish sword of the fifteenth
century. This sword is about 4 ft. long and has a wood handle
bound closely around with heavy cord. The crossbar and blade are
steel, with both edges sharp. A German poniard is shown in Fig. 4.
This weapon is about 1 ft. long, very broad, with wire or string'
bound handle, sharp edges on both sides. Another poniard of the
fourteenth century is shown in Fig. 5. This weapon is also about 1
ft. long with wood handle and steel embossed blade. A sixteenth
century German poniard is shown in Fig. 6. The blade and
ornamental crossbar is of steel, with both edges of the blade
sharp. The handle is of wood. A German stiletto, sometimes called
cuirass breakers, is shown in Fig. 7. This stiletto has a wood
handle, steel crossbar and blade of steel with both edges sharp.

In Fig. 8 is shown a short-handled flail, which is about 2-1/2 ft.
long with a dark handle of wood, studded with brass or steel
nails. A steel band is placed around the handle near the top. The
imitation of the steel band is made by gluing a piece of tinfoil
on a strip of cardboard and tacking it to the handle. A large
screw-eye is screwed into the top of the handle. The spiked ball
may be made of wood or clay. Cover the ball with some pieces of
linen, firmly glued on. When dry, paint it a dark brown or black.
A large screw-eye must be inserted in this ball, the same as used
on the end of the handle, and both eyes connected with a small
piece of rope twisted into shape. The rope is finished by covering
with tinfoil. Some short and heavy spike-headed nails are driven
into the ball to give it the appearance shown in the illustration.

A Russian knout is shown in Fig. 9. The lower half of the handle
is of wood, the upper part iron or steel, which can be imitated by
covering a piece of wood that is properly shaped with tinfoil. The
whole handle can be made of wood in one piece, the lower part
painted black and the upper part covered with tinfoil. A screw-eye
is screwed into the upper end. A length of real iron or steel
chain is used to connect the handle with the ball. The ball is
made as described in Fig. 8. The spikes in the ball are about 1
in. in length. These must be cut from pieces of wood, leaving a
small peg at the end and in the center about the size of a No. 20
spike. The pegs are glued and inserted into holes drilled into the
ball.

In Fig. 10 is shown a Sclavonic horseman's battle-axe which has a
handle of wood painted dark gray or light brown; the axe is of
steel. The blade is cut from a piece of 1/4-in. wood with a
keyhole saw. The round part is made thin and sharp on the edge.
The thick hammer side of the axe is built up to the necessary
thickness to cover

[Illustration: Ancient Weapons]

the handle by gluing on pieces of wood the same thickness as used
for the blade, and gradually shaping off to the middle of the axe
by the use of a chisel, finishing with sandpaper and covering with
tinfoil. Three large, round-headed brass or iron nails fixed into
the front side of the handle will complete the axe.

At the beginning of the sixteenth century horseman's battle-axes
shaped as shown in Fig. 11 were used. Both handle and axe are of
steel. This axe is made similar to the one described in Fig. 10.
When the woodwork is finished the handle and axe are covered with
tinfoil.



** How to Make a Round Belt Without Ends [243]

A very good belt may be made by laying several strands of strong
cord, such as braided fishline, together as shown in Fig. 1 and
wrapping them as

[Illustration: Method of Forming the Belt]

shown in Fig. 2. When wrapped all the way around, the ends are
tied and cut off. This will make a very good flexible belt; will
pull where other belts slip, and as the tension members are all
protected from wear, will last until the wrapping member is worn
through without being weakened.
--Contributed by E. W. Davis, Chicago.



** Old-Time Magic - The Growing Flower [244]

This trick is performed with a wide-mouthed jar which is about 10
in. high. If an earthern jar of this kind is not at hand, use a
glass fruit jar and cover it with black cloth or paper, so the
contents cannot be seen.

[Illustration: Flower Grows Instantly]

Two pieces of wire are bent as shown in Fig. 1 and put together as
in Fig. 2. These wires are put in the jar, about one-third the way
down from the top, with the circle centrally located. The wires
can be held in place by carefully bending the ends, or using small
wedges of wood.

Cut a wire shorter in length than the height of the jar and tie a
rose or several flowers on one end. Put a cork in the bottom of
the jar and stick the opposite end of the wire from where the
flowers are tied through the circle of the two wires and into the
cork. The dotted lines in Fig. 3 show the position of the wires
and flowers.

To make the flowers grow in an instant, pour water into the jar at
one side of the wide mouth. The cork will float and carry the wire
with the flowers attached upward, causing the flowers to grow,
apparently, in a few seconds' time. Do not pour in too much water
to raise the flowers so far that the wire will be seen.
--Contributed by A. S. Macdonald, Oakland, Calif.



** Water and Wine Trick [244]

This is an interesting trick based on the chemical properties of
acids and alkalies. The materials needed are: One glass pitcher,
filled with water, four glass tumblers, an acid, an alkali and
some phenolphthalein solution which can be obtained from your
local druggist. Before the performance, add a few drops of the
phenolphthalein to the water in the pitcher and rub a small
quantity of the alkali solution on the sides of two of the
tumblers and repeat, only using as large a quantity of the acid as
will escape notice on the remaining tumblers. Set the tumblers so
you will know which is which and proceed as follows: Take hold of
a prepared tumbler with the left hand and pour from the pitcher,
held in the right hand, some of the liquid. The liquid turned into
the glass will become red like wine. Set this full tumbler aside
and take the pitcher in the left hand and pour some of the liquid
in one of the tumblers containing the acid as it is held in the
right hand. There will be no change in color. Repeat both parts in
the same order then begin to pour the liquids contained in the
tumblers back into the pitcher in the order reversed and the
excess of acid will neutralize the alkali and cause it to lose its
color and in the end the pitcher will contain a colorless liquid.
--Contributed by Kenneth Weeks, Bridgeton, N.J.



** Cheap Nails are Expensive [244]

The life of iron shingle nails is about 6 years. An iron nail
cannot be used again in putting on a new roof. Solid zinc nails
last forever and can be used as often as necessary. As zinc is
much lighter than iron, the cost of zinc nails is only about 2-1/2
times that of iron nails.



** Cutting Lantern Slide Masks [245]

It has long been a puzzle to me why round cornered masks are
almost invariably used for lantern slides, when most works of art
are included within rectangular spaces, says a correspondent of
Photo Era. Certainly the present commercial masks are in very poor
taste. The worker who wishes to make the most of every slide will
do well to cut his own masks, not only because of the fact just
mentioned, but also because he can suit the size of the opening to
the requirements of each slide. Slides can be works of art just as
much as prints; so that masking a slide becomes just as important
as trimming a print, and equally worthy of individual treatment.
It is folly to give each slide a mask opening of uniform size and
shape.

When many slides are to be masked, it becomes tedious work to
treat each one separately, unless some special device is used. The
accompanying drawing shows a way to mark masks which is simple,
practical and costs nothing. The drawing is exactly lantern slide
size.

Lay the slide over such a guide and note the size of the opening
best suited to the picture. This will be determined by the
intersection of the ruled lines, which are numbered for
convenience in working. If the size wanted is No. 4 for width and
No. 2 for height, place the guide over a piece of black mask paper
and prick through the proper intersections with the point of a
pin. This outlines the desired

[Illustration: Form for Marking Out Rectangular Lantern Slide
Masks]

opening, which may then be cut out easily with a knife and
straight edge.

The black paper from plate boxes and film rolls is excellent for
making masks. It should be cut up in pieces 3-1/4 by 4 in. and
kept ready for use at any time.



** Relieving the Weight of a Talking Machine Reproducer [245]

Too loud reproduction from a record, the scratching noise
sometimes heard and the forcing of the needle into a soft record,
because the extension arm and reproducer are too heavy, can be
remedied in the following manner: Attach a small ring to the under
side of the horn and use a rubber band to lift the extending arm
slightly.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** How to Make a Thermometer Back in Etched Copper [246]

Etching copper is not a very difficult process. Secure a sheet of
No. 16 gauge copper of the width and length

[Illustration: Copper Thermometer Holder]

wanted for the back of the thermometer. In the design shown the
extreme width is 3-1/2 in. and the extreme length 7 in.

Draw a design. The one shown is merely suggestive. The worker may
change the outline or proportions as desired. The decoration, too,
may be changed. The essential thing is to keep a space upon which
to place the thermometer. This design is in what is known as
two-part symmetry. A line is drawn down the paper and one-half of
the outline and decoration worked out. This done, the paper is
folded along the center line, a piece of carbon paper is inserted
between the folds and the design transferred on the inner surfaces
by tracing with a pencil over the half of the outline previously
drawn. Trace the design and outline upon the metal, using the
carbon paper.

Cut out the outline with metal shears and file the edges smooth.

With a small brush and ordinary asphaltum or black varnish, paint
the design, the margin and the entire back of the metal. When this
coat has dried put on a second and then a third. The asphaltum is
to keep the acid into which the metal is to be immersed later from
eating any part of the metal but the background. Two coats or more
are needed to withstand the action of the acid.

The acid bath is composed of nitric acid and water, about half and
half, or, possibly, a little less acid than water, the mixture
being made by pouring the acid into the water, not the water into
the acid, which is dangerous. Keep this solution off the hands and
clothes, and do not inhale the fumes.

Put the asphalt-coated metal in the bath and allow it to remain
for four or five hours, depending upon the thickness of the metal
and the strength of the acid. With a stick, or a pair of old
tongs, take the metal out of the acid occasionally and examine it
to see how deep the acid has eaten it--1/32 in. is about right for
the No. 16 gauge.

When etched to the desired depth, remove the piece and with an old
knife' scrape off the asphaltum. Finish the cleaning by scrubbing
with turpentine and a brush having stiff bristles.

If the metal is first covered with turpentine and then heated over
a flame, all the colors of the rainbow will appear on its surface.
These colors fade away in the course of a long time, but they can
be easily revived. Another way to get these colors is to heat the
metal and then plunge it into the acid bath quickly.

A green finish is obtained by painting the background with an acid
stain composed as follows: 1 part ammonia muriate; 3 parts ammonia
carbonate; 24 parts water. If one coat does not give the depth of
color desired, repeat as many times as is necessary, allowing each
coat time to dry before applying the next.

To "fix" this color so that it will not rub off, and to keep the
metal from tarnishing, apply a coat of banana oil or lacquer.

Thermometers of suitable size can be bought in either brass or
nickel. They have holes through their top and bottom ends through
which metal paper fasteners can be inserted, and these in turn put
through holes punched in the copper back.



** To Make an Electric Piano [247]

Make or buy a table, about 3 ft. long and 1 ft. or more wide, and
about 2-1/2 ft. high. Nail a board, A, Fig. 1, about 8 in. wide
and of the same length as the table, to the table, as shown in the
illustration. Paint the table any color desired.

Purchase a dozen or so battery electric bells (they are cheaper if
bought by the dozen) and screw them to the board, as in Fig. 2.
Arrange the bells in the scale shown at B, Fig. 2. Bore two holes
near the posts of each bell for the wires to pass through.

Buttons for the bells may be purchased, but it is cheaper to make
them in the following way: Take a piece of

[Illustration: How the Electric Piano is Constructed]

wood and cut it round, about 2-1/2 in. in diameter and 1/4 in.
thick, Fig. 3, and bore two holes, C and D, through it. Then get
two posts, about 1 in. long, (battery posts will do) and put them
through the holes as in Fig. 4. Cut out a piece of tin, 3/8 in.
wide, punch a hole through it and put in under post E, so that
when it is pressed down, it will touch post F. It may be either
nailed or screwed down.

Make two holes in the table for each button and its wires, as at
H, Fig. 2. Nail or screw the buttons to the table, as shown in
Fig. 5, with the wires underneath. The connections are simple: I,
Fig. 5, is a wire running from one end of the table to the other
end, attached to a post at each end; J is another wire attached in
the same way; L is the carbon wire running from the batteries to
I; M is the zinc wire running from the batteries to wire J; 0
indicates the batteries; P is a wire running from J to one post of
a button; Q is another wire running from the other post of the
button to one of the posts of the bell; R is a wire running from I
to one post of the bell. When the button S is pressed, the bell
will ring. Each button should be connected with its bell in the
same way.
--Contributed by Vincent de Ybarrondo.



** Imitation Arms and Armor - PART III [248]

Maces and battle-axes patterned after and made in imitation of the
ancient weapons which were used from the

[Illustration: Ancient Weapons]

fourteenth to the sixteenth century produce fine ornaments for the
hall or den, says the English Mechanic. The imitation articles are
made of wood, the steel parts represented by tinfoil stuck on with
glue and the ornaments carved out with a carving tool.

An English mace used about the middle of the fifteenth century is
shown in Fig. 1. The entire length of this weapon is about 24 in.;
the handle is round with a four-sided sharp spike extending out
from the points of six triangular shaped wings. Cut the handle and
spike from one piece of wood and glue the wings on at equal
distances apart around the base of the spike. The two bands or
wings can be made by gluing two pieces of rope around the handle
and fastening it with tacks. These rings can be carved out, but
they are somewhat difficult to make. After the glue is dry, remove
all the surplus that has been pressed out from the joints with the
point of a sharp knife blade and then sandpaper the surface of the
wood to make it smooth. Secure some tinfoil to cover the parts in
imitation of steel. A thin coat of glue is quickly applied to the
surface of the wood and the tinfoil laid on evenly so there will
be no wrinkles and without making any more seams than is
necessary. The entire weapon, handle and all, is to appear as
steel.

An engraved iron mace of the fifteenth century is shown in Fig. 2.
This weapon is about 22 in. long, mounted with an eight-sided or
octagonal head. It will be easier to make this mace in three
pieces, the octagonal head in one piece and the handle in two
parts, so that the circular shield shown at the lower end of the
handle can be easily placed between the parts. The circular piece
or shield can be cut from a piece of wood about 1/4 in. thick. The
circle is marked out with a compass. A hole is made through the
center for the dowel of the two handle parts when they are put
together. A wood peg about 2 in. long serves as the dowel. A hole
is bored in the end of both handle pieces and these holes well
coated with glue, the wood peg inserted in one of them, the shield
put on in place and handle parts put together and left for the
glue to set. The head is fastened on the end of the handle with a
dowel in the same manner as putting the handle parts together.

The head must have a pattern sketched upon each side in pencil
marks, such as ornamental scrolls, leaves, flowers, etc. These
ornaments must be carved out to a depth of about 1/4 in. with a
sharp carving tool. If such a tool is not at hand, or the amateur
cannot use it well, an excellent substitute will be found in using
a sharp-pointed and red-hot poker, or pieces of heavy wire heated
to burn out the pattern to the desired depth. The handle also has
a scroll to be engraved. When the whole is finished and cleaned

[Illustration: Battle Axes of the Fourteenth, Fifteenth and
Sixteenth Centuries]

Up, it is covered with tinfoil in imitation of steel. The tinfoil
should be applied carefully, as before mentioned, and firmly
pressed into the engraved parts with the finger tips or thumb.

A French mace used in the sixteenth century is shown in Fig. 3.
This weapon is about 22 in. long and has a wood handle covered
with dark red cloth or velvet, the lower part to have a gold or
red silk cord wound around it, as shown, the whole handle finished
off with small brass-headed nails. The top has six ornamental
carved wings which are cut out, fastened on the handle and covered
with tinfoil, as described in Fig. 2.

Figure 4 shows a Morning Star which is about 26 in. long. The
spiked ball and the four-sided and sharp-pointed spike are of
steel. The ball may be made of clay or wood and covered with
tinfoil. The spikes are cut out of wood, sharp-pointed and
cone-shaped, the base having a brad to stick into the ball. The
wood spikes are also covered with tinfoil. The handle is of steel
imitation, covered in the middle with red cloth or velvet and
studded with large-headed steel nails.

A war hammer of the fifteenth century is shown in Fig. 5. Its
length is about 3 ft. The lower half of the handle is wood.
covered with red velvet, with a golden or yellow cord wound
spirally over the cloth. The upper half of the handle is steel,
also, the hammer and spike. The entire handle should be made of
one piece, then the hammer put on the base of the spike. The spike
made with a peg in its lower end and well glued, can be firmly
placed in position by the peg fitting in a hole made for its
reception in the top of the handle. Finish up the steel parts with
tinfoil.

The following described weapons can be constructed of the same
materials and built up in the same way as described in the
foregoing articles: A horseman's short-handled battle-axe, used at
the end of the fifteenth century, is shown in Fig. 6. The handle
is of wood and the axe in imitation steel. Figure 7 shows an
English horseman's battle-axe used at the beginning of the reign
of Queen Elizabeth. The handle and axe both are to be shown in
steel. A German foot soldier's poleaxe used, at the end of the
fourteenth century is shown in Fig. 8. The handle is made of dark
wood and the axe covered with tinfoil. Figure 9 shows an English
foot soldier's jedburgh axe of the sixteenth century. The handle
is of wood, studded with large brass or steel nails. The axe is
shown in steel. All of these axes are about the same length.



** Playing Baseball with a Pocket Knife [250]

An interesting game of baseball can be played by two persons with
a common pocket knife on a rainy day or in

[Illustration: Positions of the Knife Indicate the Plays]

the winter time when the regular game cannot be played outdoors.
The knife is opened and loosely stuck into a board, as in Fig. 1,
and with a quick upward movement of the forefinger it is thrown
into the air to fall and land in one of the positions shown. The
plays are determined by the position of the knife after the fall.

A foul ball is indicated by Fig. 2, the knife resting on its back.
The small blade sticking in the board which holds the handle in an
upright position, as shown in Fig. 3, calls for a home run. Both
blades sticking in the board (Fig. 4), a three-base hit. A
two-base hit is made when the large blade sticks in the board,
Fig. 5. A one-base hit is secured when the large blade and the end
of the handle touch the board as in Fig. 6. The knife falling on
its side (Fig. 7) calls for one out. Each person plays until three
outs have been made, then the other plays, and so on for nine
innings.
--Contributed by Herbert Hahn, Chicago.



** How to Remove Paper Stuck to a Negative [250]

When making photographic prints from a negative, sometimes a drop
of moisture will cause the print to stick to the gelatine film on
the glass. Remove as much of the paper as can be readily torn off
and soak the negative in a fresh hypo bath of 3 or 4 oz. hypo to 1
pt. of water for an hour or two. Then a little gentle rubbing with
the finger-not the finger nail will remove anything adhering to
the film. It may be found that the negative is not colored. If it
is spotted at all, the negative must be washed for a few minutes
and placed in a combined toning and fixing bath, which will remove
the spots in a couple of hours. The negative must be well washed
after going through the solutions to take away any trace of hypo.



** Old-Time Magic - A Sack Trick [251]

The magician appears accompanied by his assistant. He has a sack
similar to a meal bag only on a large scale. The upper end of this
bag is shown in Fig. 1, with the rope laced in the cloth. He then
selects several people from the audience as a committee to examine
the sack to see that there is absolutely no deception whatever in
its makeup. When they are satisfied that the bag or sack is all
right, the magician places his assistant inside and drawing the
bag around him he allows the committee to tie him up with as many
knots as they choose to make, as shown in Fig. 2.

The bag with its occupant is placed in a small cabinet which the
committee surround to see that there is no outside help. The
magician then takes his watch and shows the audience that in less
than 30 seconds his assistant will emerge from the cabinet with
the sack in his hand. This he does, the sack is again examined and
found to be the same as when it was first seen.

[Illustration: Sack Trick-Holding the Rope Inside the Bag]

The solution is when the assistant enters the bag he pulls in
about 15 in. of the rope and holds it, as shown in Fig. 3, while
the committee is tying him up. As soon as he is in the cabinet he
merely lets out the slack thus making enough room for his body to
pass through. When he is out of the bag he quickly unties the
knots and then steps from his cabinet.
--Contributed by J. F. Campbell, Somerville, Mass.



** The Invisible Light [251]

The magician places two common wax candles on a table, one of them
burning brightly, the other without a light. Members of the
audience are allowed to inspect both the table and the candles.

The magician walks over to the burning candle, shades the light
for a few seconds, turns to the audience with his hands a few
inches apart, showing that there is nothing between them, at the
same time saying that he has a light between his hands, invisible
to them (the audience), with which he is going to light the other
candle. He then walks over to the other candle, and, in plain
sight of the audience lights the candle apparently with nothing.

In reality the magician has a very fine wire in his hand which he
is heating while he bends over the lighted candle, and the
audience gaze on and see nothing. He turns to the other candle and
touches a grain of phosphorus that has been previously concealed
in the wick with the heated wire, thus causing it to light.
--Contributed by C. Brown, New York City.



** Using the Sun's Light in a Magic Lantern [251]

The light furnished with a small magic lantern does very well for
evening exhibitions, but the lantern can be used in the daytime
with good results by directing sunlight through the lens instead
of using the oil lamp. A window facing the sun is selected and the
shade is drawn almost down, the remaining space being covered by a
piece of heavy paper. A small hole is

[Illustration: Magic Lantern]

cut in the paper and the lantern placed on a table in front of the
hole, the lamp having been removed and the back opened. The
lantern must be arranged so that the lens will be on a horizontal
line with the hole in the paper. A mirror is then placed just
outside of the window and at such an angle that the beam of light
is thrown through the hole in the paper and the lens of the
lantern.

The shades of the remaining windows are then drawn and the lantern
is operated in the usual way.
--Contributed by L. B. Evans, Lebanon, Ky.



** A Handy Drill Gauge [252]

The accompanying sketch shows a simple drill gauge which will be
found very handy for amateurs. The gauge consists of a piece of
hard wood, 3/4 in. thick, with a width and length that will be
suitable for the size and number of drills you have on hand. Drill
a hole through the wood with each drill you have and place a screw
eye in one end to be used as a hanger. When you want to drill a
hole for a pipe, bolt,

[Illustration: Drill Gauge]

screw, etc., you take the gauge and find what size drill must be
used in drilling the hole.-Contributed by Andrew G. Thome,
Louisville, Ky.



** Stove Polish [252]

A good stove polish can be made by mixing together 1 lb. of
plumbago, 4 oz. of turpentine, 4 oz. of water and 1 oz. of sugar.
Mix well and apply with a cloth or brush.

A Home-Made Daniell Cell [252]

An effective Daniell galvanic cell may be constructed from
material costing very little money. A common tin tomato can with a
copper wire soldered to the top forms the jar and positive
electrode. A piece of discarded stove zinc rolled into an open
cylinder of about 1-1/2-in. diameter, 5 in. long, with a copper
wire soldered at one end forms the negative electrode.

To make the porous cell, roll a piece of heavy brown wrapping
paper, or blotting paper, into a tube of several thicknesses,
about 5 in. long with an internal diameter of 2 in. Tie the paper
firmly to prevent unrolling and close up one end with plaster of
paris 1/2 in. thick. It is well to slightly choke the tube to
better retain the plaster. The paper used must be unsized so that
the solution scan mingle through the pores.

Two liquids are necessary for the cell. Make a strong solution in
a glass or wooden vessel of blue vitriol in water. Dilute some oil
of vitriol (sulphuric acid) with about 12 times its measure of
water and keep in a bottle when not in use. In making up the
solution, add the acid to the water with constant stirring. Do not
add water to the acid.

The cell is charged by placing the zinc in the paper tube and both
placed into the tin can. Connect the two wires and pour the dilute
acid into the porous cell around the zinc, and then immediately
turn the blue vitriol solution into the can outside the paper cup.

A current generates at once and metallic copper begins to deposit
on the inside of the can. It is best to let the action continue
for a half hour or so before putting the cell into use.

[Illustration: Daniell Cell]

Several hours working will be required before the film of copper
becomes sufficiently thick to protect the tin from corrosion when
the cell stands idle. For this reason it will be necessary to pour
out the blue vitriol solution into another receptacle immediately
after through using, as otherwise the tin would be soon eaten full
of holes. The porous cup should always be emptied after using to
prevent the diffusion of the blue vitriol solution into the cup,
and the paper tube must be well rinsed before putting away to dry.

This makes one of the most satisfactory battery cells on account
of the constancy of its current, running for hours at a time
without materially losing strength, and the low cost of
maintenance makes it especially adapted for amateurs' use. Its
current strength is about one volt, but can be made up into any
required voltage in series. A battery of a dozen cells should cost
not to exceed 50 cts. for the material, which will give a strong,
steady current, amply sufficient for all ordinary experimental
work.

A strong solution of common salt may be used in place of the oil
of vitriol in the porous cup, but is not so good.
--Contributed by C. H. Denniston, Pulteney. N. Y.



** A Home-Made Equatorial [253]
By Harry Clark

The ordinary equatorial is designed and built for the latitude of
the observatory where it is to be used. This is necessary since
the hour axis must point to the north pole of the heavens whose
elevation above the horizon is equal to the latitude of the
observer's station. The final adjustment of an ordinary equatorial
is very tedious so that when once set up it is not to be moved.
This calls for a suitable house to protect the instrument. It has
been the aim of the writer to build a very simple instrument for
amateur work which would be adjustable to any latitude, so easily
set up ready for work and so portable that it need not be left out
of doors from one evening until the next.

[Illustration: Instrument for Locating Stars]

The instrument is mounted on a tripod or piece of iron pipe
carrying a short vertical rod of 3/8-in. steel. A rectangular
wooden frame with suitable bearings rotates about this shaft. The
frame has also two horizontal bearings carrying a short shaft to
the end of which the frame carrying the hour axis is firmly
clamped. By this arrangement of two perpendicular shafts the hour
axis may be directed to any point in the heavens without care as
to how the tripod or pipe is set up.

The frame for the hour axis is about 12 in. long with a bearing at
each end. The shaft which it carries is 1/4-in. steel, carrying
the hour circle at one end, and at the other the frame for the
declination axis which is similar to the other, but somewhat
lighter. The declination axis is also of 1/4-in. steel, carrying
at one end the declination circle and the pointer at the other.

The entire frame of the instrument is made of cherry and it will
save the builder much time if he will purchase cherry "furniture"
which is used by printers and can be obtained from any printers'
supply company. It is best quality wood free from imperfections in
straight strips one yard long and of a uniform width of about 5/8
in. As to thickness, any multiple of 12-point (about 1/8 in.) may
be obtained, thus saving much work in fitting up joints. Fifty
cents will buy enough wood for an entire instrument. All corners
are carefully mortised and braced with small brass angle-pieces.
The frame is held together by small brass machine screws. After
much experimentation with bearings, it was found best to make them
in halves as metal bearings are usually made. The loose half is
held in place by guides on all four sides and is tightened by two
screws with milled nuts. A great deal of trouble was experienced
in boring out the bearings until the following method was devised.
One hole was bored as well as possible. The bearing was then
loosened and a bit run through it to bore the other. Finally, a
piece of shafting was roughened by rolling it on a file placed in
both bearings and turned with a brace. The bearings were gradually
tightened until perfectly ground.

The declination axis must be perpendicular to both the hour axis
and the line of sight over the pointer. To insure this, a positive
adjustment was provided. The end of the shaft is clamped in a
short block of wood by means of a bearing like the ones described.
One end of the block is hinged to the axis frame, while the other
end is attached by two screws, one drawing them together, the
other holding them apart. The axis is adjusted by turning these
screws. Each shaft, save the one in the pipe, is provided with
this adjustment.

The pointer is of two very thin strips placed at right angles and
tapered slightly at each end. The clamp is attached as shown in
the illustration. The eye piece is a black iron washer supported
on a small strip of wood. The aperture should be 1/4 in., since
the pupil of the eye dilates very much in darkness. The error due
to large aperture is reduced by using a very long pointer which
also makes it possible to focus the eye upon the front sight and
the star simultaneously. The forward sight is a bright brass peg
illuminated by a tiny electric lamp with a reflector to shield the
eye. The pointer arranged in this way is a great improvement over
the hollow tube sometimes used, since it allows an unobstructed
view of the heavens while indicating the exact point in question.

The circles of the instrument are of aluminum, attached to the
shafts by means of wooden clamps. They were nicely graduated by a
home-made dividing engine of very simple construction, and the
figures were engraved with a pantograph. The reading is indicated
by a cut on a small aluminum plate attached to a pointer. The hour
circle is divided into 24 parts and subdivided to every four
minutes. The figures are arranged so that when the instrument is
set up, the number of hours increases while the pointer travels
oppositely to the stars. The declination circle is graduated from
zero to 90 deg. in each direction from two points 180 deg. apart.
It is, adjusted to read zero when the pointer and two axes are
mutually perpendicular as shown in the picture.

To adjust the instrument it is set up on the iron pipe and the
pointer directed to some distant object. All set screws, excepting
those on the declination axis, are tightened. Then the pointer is
carefully turned through 180 deg. and if it is not again directed
to the same point, it is not perpendicular to the declination
axis. When properly set it will describe a great circle. With the
declination axis in an approximately horizontal position the place
where the pointer cuts the horizon is noted. The declination axis
is then turned through 180 deg., when the pointer should again cut
at the same place. Proper adjustment will cause it to do so. It is
desirable that the hour circle should read approximately zero when
the declination axis is horizontal, but this is not necessary for
a reason soon to be explained. All these adjustments, once
carefully made, need not be changed.

In using the instrument the hour axis can be directed to the north
pole by the following method. Point it approximately to the north
star. The pole is 1 deg. and 15 min. from the star on a straight
line from the star to "Mizar," the star at the bend of the handle
in the Big Dipper. Turn the hour circle into a position where the
pointer can describe a circle through "Mizar." Only a rough
setting is necessary. Now turn the pointer so that a reading of 88
deg. 45 min. shows on the declination circle on that side of 90
which is toward "Mizar." When this is done, clamp both axes and
turn the shafts in the base until the pointer is directed
accurately to the north star. It is evident from a study of the
picture that the position of the small pointer which indicates the
reading on the hour circle is not independent of the way in which
the tripod or pipe is set up. It would then be useless to adjust
it carefully to zero when the pointer cuts the "zenith" as is done
with a large equatorial. Instead, the adjustment is made by
setting the clock or watch which is part of the outfit. The
pointer is directed to Alpha, Cassiopiae, and the hour reading
subtracted from 24 hours (the approximate right ascension of the
star) gives the time which the clock should be set to indicate.
All of these settings should require not more than five minutes.

To find a star in the heavens, look up its declination and right
ascension in an atlas. Set the declination circle to its reading.
Subtract the clock time from the right ascension (plus 24 if
necessary) and set the hour circle to the result. The star will
then be seen on the tip of the pointer.

To locate a known star on the map, turn the pointer to the star.
Declination is read directly. Add the clock time to the hour
reading to get right ascension. If the result is more than 24
hours, subtract 24.



** A Ground Glass Substitute [255]

Ordinary plain glass coated with the following mixture will make a
good ground glass substitute: Dissolve 18 gr. of gum sandarac and
4 gr. of gum mastic in 3-1/2 dr.. of ether, then add 1 2-3 dr.
benzole. If this will be too transparent, add a little more
benzole, taking care not to add too much. Cover one side of a
clear glass and after drying it will produce a perfect surface for
use as a ground glass in cameras.
--Contributed by Ray E. Strosnider, Plain City, Ohio.



** A Miniature War Dance [255]

A piece of paper, 3 or 4 in. long, is folded several times, as
shown in the sketch, and the first fold marked out to represent
one-half of an Indian. Cut out all the folds at one time on the
dotted line and you will have as many men joined together as there
were folds in the paper. Join the hands of the two end men with a
little paste so as to form a circle of Indians holding hands.

The next thing to do is to punch holes in heavy cardboard that is
large enough to cover a pot or stew pan, and

[Illustration: Indian War Dance]

partially fill the vessel with water. Set this covered vessel over
a heat and bring the water to a boiling point and then set the
miniature Indians on the perforated cover. The dance will begin.

If the Indians are decked out with small feathers to represent the
head gear and trailing plumes, a great effect will be produced.
--Contributed by Maurice Baudier, New Orleans, La.



** Saving an Engine [255]

Turning the water on before starting the gas engine may prevent
breaking a cylinder on a cold day.



** OLD-TIME MAGIC [256]

Removing 36 Cannon Balls from a Handbag

The magician produces a small handbag and informs the audience
that he has it filled with 20-lb. cannon balls. He opens up the
bag and takes out a ball which he passes to the audience

[Illustration: Balls Made of Spring Wire]

for examination. The ball is found to be the genuine article. He
makes a few passes with the wand and produces another ball, and so
on until 36 of them lie on the floor.

In reality the first ball, which is the one examined, is the real
cannon ball, the others are spiral-spherical springs covered with
black cloth (Fig. 1). These balls can be pressed together in flat
disks and put in the bag, Fig. 2. without taking up any great
amount of space. When the spring is released it will fill out the
black cloth to represent a cannon ball that cannot be
distinguished from the real article.
--Contributed by J. F. Campbell, Somerville, Mass.



** A Rising Card Trick [256]

A rising card trick can be accomplished with very little skill by
using the simple device illustrated. The only

[Illustration: Card Slips from the Pack]

things needed are four ordinary playing cards and a short rubber
band. Pass one end of the rubber band through one card and the
other end through the other card, as shown in the illustration,
drawing the cards close together and fastening the ends by putting
a pin through them. The remaining two cards are pasted to the
first two so as to conceal the pins and ends of the rubber band.

Put the cards with the rubber band in a pack of cards; take any
other card from the pack and show it to the audience in such a way
that you do not see and know the card shown. Return the card to
the pack, but be sure and place it between the cards tied together
with the rubber band. Grasp the pack between your thumb and finger
tightly at first, and by gradually loosening your hold the card
previously shown to the audience will slowly rise out of the pack.
--Contributed by Tomi O'Kawara, San Francisco, Cal.



** Sliding Box Cover Fastener [256]

[Illustration: Box with Fastener]

While traveling through the country as a watchmaker I found it
quite convenient to keep my small drills, taps, small brooches,
etc., In boxes having a sliding cover. To keep the contents from
spilling or getting mixed in my case I used a small fastener as
shown in the accompanying illustration, The fastener is made of
steel or brass and fastened by means of small screws or tacks on
the outside of the box. A hole is drilled on the upper part to
receive the pin that is driven into the sliding cover. This pin
should not stick out beyond the thickness of the spring, which is
bent up at the point so the pin will freely pass under it. The pin
can be driven through the cover to prevent it from being pulled
entirely out of the box.
--Contributed by Herm Grabemann, Milwaukee, Wis.



** How to Chain a Dog [257]

A good way to chain a dog and give him plenty of ground for
exercise is to stretch a clothesline or a galvanized

[Illustration: The Dog Has Plenty of Room for Exercise]

wire between the house and barn on which is placed a ring large
enough to slide freely. The chain from the dog's collar is
fastened to the ring. This method can also be used for tethering a
cow or horse, the advantage being the use of a short tie rope
eliminating the possibility of the animal becoming entangled.



** Water-Color Box [257]

There are many different trays in the market for the purpose of
holding water colors, but they are either too expensive for the
average person or too small to be convenient. I do a great deal of
water-color work and always felt the need of a suitable color
dish. At last I found something that filled my want and suited my
pocketbook. I bought 22 individual salt dishes and made a box to
hold them, as shown in the illustration. This box has done good
service.

Some of the advantages are: Each color is in a separate dish which
can be easily taken out and cleaned; the dishes are deep enough to
prevent spilling the colors into the adjoining ones, and the box
can be made as big or as small as individual needs require. The
tray containing the color dishes and brushes rests on 1/4-in.
round pieces 2-1/4 in. from the bottom of the box, thus giving
ample store room for colors, prints, slides and extra brushes.

[Illustration: Color Trays Made of Salt Dishes]

--Contributed by B. Beller, Hartford, Connecticut.



** Saving Ink Pens [257]

Ink usually corrodes pens in a short time. This can be prevented
by placing pieces of steel pens or steel wire in the ink, which
will absorb the acid and prevent it from corroding the pens.



** A Plant-Food Percolator [258]

Obtain two butter tubs and bore a large number of 1/4-in. holes in
the bottom of one, then cover the perforated part with a piece of
fine brass gauze (Fig. 1), tacking the gauze well at the corners.
The other tub should be fitted with a faucet of some kind--a wood
faucet, costing 5 cents, will answer the purpose. Put the first
tub on top of the other with two narrow strips between them (Fig.
2). Fill the upper tub, about three-fourths full, with well packed
horse manure, and pour water on it until it is well soaked. When
the water has percolated through into the lower tub, it is ready
to use on house and garden plants and is better than plain water,
as it adds both fertilizer and moisture.
--Contributed by C. O. Darke, West Lynn, Mass.

[Illustration: FIG.1, Fig. 2]



** Lathe Safety [258]

Always caliper the work in a lathe while it is standing still.
Never use the ways of a lathe for an anvil or storage platform.



** Folding Quilting-Frames [258]

The frame in which the material is kept stretched when making a
quilt is usually too large to be put out of the way conveniently
when other duties must be attended to; and especially are the end
pieces objectionable. This can be remedied by hinging the ends so
they will fold underneath to the center. The end pieces are cut in
two at one-fourth their distance from each end, a hinge screwed to
the under side to hold them together, and a hook and eye fastened
on the other side to hold the parts rigid when they are in use.
When the ends are turned under, the frame is narrow enough to be
easily carried from one room to another, or placed against a wall.



** A Drip Shield for the Arms [258]

When working with the hands in a pan of water, oil or other fluid,
it is very disagreeable to have the liquid run down the arms, when
they are raised from the pan, often to soil the sleeves of a clean
garment. A drip shield which will stop the fluid and cause it to
run back into the pan can be easily made from a piece of sheet
rubber or, if this is not available, from a piece of the inner
tube of a bicycle tire. Cut a washer with the hole large enough to
fit snugly about the wrist, but not so tight as to stop the

[Illustration: Shields for the Arms]

circulation of the blood. A pair of these shields will always come
in handy.
--Contributed by L. M. Eifel, Chicago.



** How to Cane Chairs [259]

There are but few households that do not have at least one or two
chairs without a seat or back. The same households may have some
one who would enjoy recaning the chairs if he only knew how to do
it, and also make considerable pin money by repairing chairs for
the neighbors. If the following directions are carried out, new
cane seats and backs can easily be put in chairs where they are
broken or sagged to an uncomfortable position.

The first thing necessary is to remove the old cane. This can be
done by turning the chair upside down and, with the aid of a sharp
knife or chisel, cutting the cane between the holes. After this is
done the old bottom can be pulled out. If plugs are found in any
of the holes, they should be knocked out. If the beginner is in
doubt about finding which holes along any curved sides should be
used for the cane running nearly parallel to the edge, he may find
it to his advantage to mark the holes on the under side of the
frame before removing the old cane.

The worker should be provided with a small sample of the old cane.
At any first-class hardware store a bundle of similar material may
be secured.

The cane usually comes in lengths of about 15 ft. and each bundle
contains

[Illustration: Three Stages of Weaving]

enough to reseat several chairs. In addition to the cane, the
worker should provide himself with a piece of bacon rind, a square
pointed wedge, as shown in Fig. 1, and 8 or 10 round wood plugs,
which are used for temporarily holding the ends of the cane in the
holes.

[Illustration: First Layer of Strands]

A bucket of water should be supplied in which to soak the cane
just before weaving it. Several minutes before you are ready to
begin work, take four or five strands of the cane, and, after
having doubled them up singly into convenient lengths and tied
each one into a single knot, put them into the water to soak. The
cane is much more pliable and is less liable to crack in bending
when worked while wet. As fast as the soaked cane is used, more of
it should be put into the water.

Untie one of the strands which has been well soaked, put about 3
or 4 in. down through the hole at one end of what is to be the
outside strand of one side and secure it in this hole by means of
one of the small plugs mentioned. The plug should not be forced in
too hard nor cut off, as it must be

[Illustration: First Two Layers in Place]

removed again. The other end of the strand should be made pointed
and passed down through the hole at the opposite side, and, after
having been pulled tight, held there by inserting another plug.
Pass the end up through the next hole, then across and down, and
hold while the second plug is moved to the last hole through which
the cane was drawn. In the same manner proceed across the chair
bottom. Whenever the end of one strand is reached, it should be
held by a plug, and a new one started in the next hole as in the
beginning. No plugs should be permanently removed until another
strand of cane is through the same hole to hold the first strand
in place. After laying the strands across the seat in one
direction, put in another layer at right angles and lying entirely
above the first layer. Both of these layers when in place appear
as shown in one of the illustrations.

After completing the second layer, stretch the third one, using
the same holes as for the first layer. This will make three
layers, the first being hidden by the third while the second layer
is at right angles to and between the first and third. No weaving
has been done up to this time, nothing but stretching and
threading the cane through the holes. The cane will have the
appearance shown in Fig. 3. The next thing to do is to start the
cane across in the same direction as the second layer and begin
the weaving. The top or third layer strands should be pushed
toward the end from which the weaving starts, so that the strand
being woven may be pushed down between the first and third layers
and up again between pairs. The two first strands of the fourth
layer are shown woven in Fig. 3. During the weaving, the strands
should be lubricated with the rind of bacon to make them pass
through with ease. Even with this lubrication, one can seldom
weave more than half way across the seat with the pointed end
before finding it advisable to pull the remainder of the strand
through. After finishing this fourth layer of strands, it is quite
probable that each strand will be about midway between its two
neighbors instead of lying close to its mate as desired, and here
is where the square and pointed wedge is used. The wedge is driven
down between the proper strands to move them into place.

Start at one corner and weave diagonally, as shown in Fig. 4,
making sure that the strand will slip in between the two which
form the corner of the square in each case. One more weave across
on the diagonal and the seat will be finished except for the
binding, as shown in Fig. 5. The binding consists of one strand
that covers the row of holes while it is held down with another
strand, a loop over the first being made every second or third
hole as desired. It will be of great assistance to keep another
chair with a cane bottom at hand to examine while recaning the
first chair.
--Contributed by M. R. W.



** Repairing a Cracked Composition Developing Tray [260]

Fill the crack with some powdered rosin and heap it up on the
outside. Heat a soldering-iron or any piece of metal enough to
melt the rosin and let it flow through the break. When cool, trim
off the surplus rosin. If handled with a little care, a tray
repaired in this manner will last a long time. The chemicals will
not affect the rosin.
--Contributed by E. D. Patrick, Detroit, Michigan.



** How to Lay Out a Sundial [261]

The sundial is an instrument for measuring time by using the
shadow of the sun. They were quite common in ancient times before
clocks and watches were invented. At the present time they are
used more as an ornamentation than as a means of measuring time,
although they are quite accurate if properly constructed. There
are several different designs of sundials, but the most common,
and the one we shall describe in this article, is the horizontal
dial. It consists of a flat circular table, placed firmly on a
solid pedestal and having a triangular plate of metal, Fig. 1,
called the gnomon, rising from its center and inclined toward the
meridian line of the dial at an angle equal to the latitude of the
place where the dial is to be used. The shadow of the edge of the
triangular plate moves around the northern part of the dial from
morning to afternoon, and thus supplies a rough measurement of the
hour of the day.

The style or gnomon, as it always equals the latitude of the
place, can be laid out as follows: Draw a line AB, Fig. 1, 5 in.
long and at the one end erect a perpendicular BC, the height of
which is taken from table No. 1. It may be necessary to
interpolate for a given latitude, as for example, lat. 41
degrees-30'. From table No. 1 lat. 42 degrees is 4.5 in. and for
lat. 40 degrees, the next smallest, it is 4.2 in. Their difference
is .3 in. for 2 degrees, and for 1 degrees it would be .15 in. For
30' it would be 1/2 of 1 degrees or .075 in. All added to the
lesser or 40 degrees, we have 4.2+.15+.075 in.= 4.42 in. as the
height of the line BC for lat. 41 degrees-30'. If you have a table
of natural functions, the height of the line BC, or the style, is
the base (5 in. in this case) times the tangent of the degree of
latitude. Draw the line AD, and the angle BAD is the correct angle
for the style for the given

[Illustration: Details of Dial]

TABLE No. 1.

Height of stile in inches for a 5in. base, for various latitudes

    Latitude Height  Latitude Height
      25      2.33     42     4.50
      26      2.44     44     4.83
      27      2.55     46     5.18
      28      2.66     48     5.55
      30      2.89     50     5.96
      32      3.12     52     6.40
      34      3.37     54     6.88
      36      3.63     56     7.41
      38      3.91     58     8.00
      40      4.20     60     8.66

latitude. Its thickness, if of metal, may be conveniently from
1/8 to 1/4 in. ; or if of stone, an inch or two, or more, according
to the size of the dial. Usually for neatness of appearance the
back of the style is hollowed as shown. The upper edges which
cast the shadows must be sharp and straight, and for this size
dial (10 in. in diameter) they should be about 7-1/2 in. long.

To layout the hour circle, draw two parallel lines AB and CD,
Fig. 2, which will represent the base in length and thickness.
Draw two semi-circles, using the points A and C as centers,
with a radius of 5 in. The points of intersection with the lines
AB and CD will be the 12 o'clock marks. A line EF drawn
through the points A and C, and perpendicular to the base or
style, and intersecting the semicircles, gives the 6 o'clock
points. The point marked X is to be used as the center of the
dial. The intermediate hour and half-hour lines can be plotted
by using table No. 2 for given latitudes, placing them to the
right or left of the 12-o'clock points. For latitudes not given,
interpolate in the same manner as for the height of the style.
The

Table NO. 2.
Chords in inches for a 10 in. circle Sundial.

Lat                 HOURS OF DAY
   12-30   1   1-30   2   2-30   3   3-30  4   4-30   5   5-30
   11-30  11   10-30 10   9-30   9   8-30  8   7-30   7   6-30
20  .28  .56   .87  1.19 1.57  1.99  2.49 3.11  3.87 4.82 5.93
30  .33  .66  1.02  1.40 1.82  2.30  2.85 3.49  4.26 5.14 6.10
35  .38  .76  1.16  1.59 2.06  2.57  3.16 3.81  4.55 5.37 6.23
40  .42  .85  1.30  1.77 2.27  2.82  3.42 4.07  4.79 5.55 6.32
45  .46  .94  1.42  1.93 2.46  3.03  3.64 4.29  4.97 5.68 6.39
50  .50 1.01  1.53  2.06 2.68  3.21  3.82 4.46  5.12 5.79 6.46
55  .54 1.08  1.63  2.19 2.77  3.37  3.98 4.60  5.24 5.87 6.49
60  .57 1.14  1.71  2.30 2.89  3.49  4.10 4.72  5.34 5.93 6.52

1/4-hour and the 5 and 10-minute divisions may be spaced with the'
eye or they may be computed.

When placing the dial in position, care must be taken to get it
perfectly level and have the style at right angles to the dial
face, with its sloping side pointing to the North Pole. An
ordinary compass, after allowing for the declination, will enable
one to set the dial, or it may be set by placing it as near north
and south as one may judge and comparing with a watch set at
standard time. The dial time and the watch time should agree after
the watch has been corrected for the equation of time from table
No. 3, and for the difference between standard and local time,
changing the position of the dial until an agreement is reached.
Sun time and standard time agree only four times a year, April 16,
June 15, Sept. 2 and Dec. 25, and on these dates the dial needs no
correction. The corrections for the various days of the month can
be taken from Table 3. The + means that the clock is faster, and
the means that the dial is faster than the sun. Still another
correction must be made which is constant for each given locality.
Standard time is the correct time for longitude 750 New York, 900
Chicago, 1050 Denver and 1200 for San Francisco. Ascertain in
degrees of longitude how far your dial is east or west of the
nearest standard meridian and divide this by 15, reducing the
answer to minutes and seconds, which will be the correction in
minutes and seconds of time. If the dial is east of the meridian
chosen, then the watch is slower; if west, it will be faster. This
correction can be added to the values in table No. 3, making each
value slower when it is east of the standard meridian and faster
when it is west.

The style or gnomon with its base can be made in cement and set on
a cement pedestal which has sufficient base placed in the ground
to make it solid.

The design of the sundial is left to the ingenuity of the maker.
--Contributed by J. E. Mitchell, Sioux City, Iowa.

Table No. 3

Corrections in minutes to change.
Sun time to local mean time,- add those marked + subtract those
Marked - from Sundial lime.

    Day of month  1    10    20    30
    January      +3    +7    +11   +13
    February     +14   +14   +14
    March        +13   +11   +8    +5
    April        +4    +2    -1    -3
    May          -3    -4    -4    -3
    June         -3    +1    +1    +3
    July         +3    +5    +6    +6
    August       +6    +5    +3    +1
    September    +0    -3    -5    -10
    October      -10   -13   -15   -16
    November     -16   -16   -14   -11
    December     -11   -7    -3    +2



** Imitation Arms and Armor-Part IV [263]

The ancient arms of defense as shown in the accompanying
illustrations make good ornaments for the den if they are cut from
wood and finished in imitation of the real weapon. The designs
shown represent original arms of the sixteenth and seventeenth
centuries. As they are the genuine reproductions, each article can
be labelled with the name, adding to each piece interest and
value, says the English Mechanic, London.

Each weapon is cut from wood. The blades of the axes and the
cutting edges of the swords are dressed down and finished with
sandpaper and the steel parts represented by covering the wood
with tinfoil. When putting on the tinfoil, brush a thin coat of
glue on the part to be covered and quickly lay on the foil. If a
cutting edge is to be covered the tinfoil on one side of the blade
must overlap the edge which is pasted on the opposite side. The
other side is then covered with the tinfoil of a size that will
not quite cover to the cutting edge. After laying the foil and
allowing time for the glue to dry, wipe the surface with light
strokes up and down several times using a soft piece of cloth.

[Illustration: Partisan, Fork and Halberd]

A French partisan of the sixteenth century is shown in Fig. 1. The
weapon is 6-1/2 ft. long with a round handle having the same
circumference for the entire length which is covered with crimson
cloth or velvet and studded all over with round-headed

[Illustration: Spontoon. Glaive and Voulge]

brass nails. The spear head is of steel about 15 in. long from the
point where it is attached to the handle. The widest part of the
blade from spear to spear is about 8 in. The length of the tassel
or fringe is about 4 in.

Figure 2 shows a German military fork of the sixteenth century,
the length of which is about 5 ft. with a handle of wood bound
with heavy cord in a spiral form and the whole painted a dark
color. The entire length of the fork from the handle to the points
is about 10 in., and is coveted with tinfoil in imitation of
steel.

A Swiss halberd of the sixteenth century is shown in Fig. 3. This
combination of an axe and spear is about 7 ft. long from the point
of the spear to the end of the handle, which is square. The spear
and axe is of steel with a handle of plain dark wood. The holes in
the axe can be bored or burned out with red-hot iron rods, the
holes being about 1/4 in. in diameter.

Figure 4 shows an Austrian officers' spontoon, used about the
seventeenth century. It is about 6 ft. long with a round wooden
handle. The spear head from its point to where fixed on the handle
is about 9 in. long. The edges are sharp. The cross bar which runs
through the lower end of the spear can

[Illustration: Halberd. Ranseur and Lance]

be made in two pieces and glued into a hole on each side. The
length of this bar is about 5 in. The small circular plate through
which the bar is fixed can be cut from a piece of cardboard and
glued on the wooden spear.

A gisarm or glaive, used by Italians in the sixteenth century, is
shown in Fig. 5. The entire length is about 6-1/2 ft. The blade is
engraved steel with a length of metal work from the point of the
spear to where it joins the handle or staff of about 18 in. It has
a round wooden handle painted black or dark brown. The engraved
work must be carved in the wood and when putting the tinfoil on,
press it well into the carved depressions.

Figure 6 shows a Saxon voulge of the sixteenth century, 6 ft.
long, with a round wood handle and a steel axe or blade, sharp on
the outer edge and held to the handle by two steel bands, which
are a part of the axe. The bands can be made of cardboard and
glued on to the wood axe. These bands can be made very strong by
reinforcing the cardboard with a piece of canvas. A small curved
spear point is carved from a piece of wood, covered with tinfoil
and fastened on the end of the handle as shown. The band of metal
on the side is cut from cardboard, covered with tinfoil and
fastened on with round-headed brass or steel nails.

A very handsome weapon is the German halberd of the sixteenth
century which is shown in Fig. 7. The entire length is about 6-1/2
ft., with a round wooden handle fitted at the lower end with a
steel ornament. The length of the spear point to the lower end
where it joins on to the handle is 14 in. The extreme width of the
axe is 16 or 17 in. The outer and inner edges of the
crescent-shaped part of the axe are sharp. This axe is cut out
with a scroll or keyhole saw and covered with tinfoil.

An Italian ranseur of the sixteenth century is shown in Fig. 8.
This weapon is about 6 ft. long with a round staff or handle. The
entire length of the metal part from the point of the spear to
where it joins the staff is 15 in. The spear is steel, sharp on
the outer edges.

Figure 9 shows a tilting lance with vamplate used in tournaments
in the sixteenth century. The wood pole is covered with cloth or
painted a dark color. At the end is a four-pronged piece of steel.
The vamplate can be made of cardboard covered with tinfoil to
represent steel and studded with brass nails. The extreme length
is 9 ft.

The tassels or fringe used in decorating the handles can be made
from a few inches of worsted fringe, about 4 in. long and wound
around the handle or staff twice and fastened with brass-headed
nails.



** An Emergency Babbitt Ladle [264]

Take an old stove leg and rivet a handle on it and then break the
piece off which fastens on the stove. The large and rounding part
of the leg makes the bowl of the ladle. This ladle will be found
convenient for melting babbitt or lead.
--Contributed by R. H. Workman, Loudonville, Ohio.

[Illustration: Babbitt Ladle]



** How to Make Japanese Portieres [265]

These very useful and ornamental draperies can be easily made at
home by anyone possessing a little ingenuity. They can be made of
various materials, the most durable being bamboo, although beads
of glass or rolled paper will produce good results. Substances
such as straw, while readily adaptable

[Illustration: Bamboo and Straw Portieres]

and having a neat appearance, are less durable and will quickly
show wear. The paper beads are easily made as shown in Figs. 1, 2
and 3. In Figs. 1 and 2 are shown how the paper is cut tapering,
and as it appears after rolling and gluing down the ends. A
straight paper bead is shown in Fig. B.

The first step is to select the kind of beads desired for
stringing and then procure the hanging cord. Be sure to get a cord
of such size that the beads will slip on readily and yet have the
least possible lateral movement. This is important to secure
neatness. One end of each cord is tied to a round piece of wood,
or in holes punched in a leather strap. Iron or brass rings can be
used if desired.

Cut all the cords the same length, making allowance for the number
of knots necessary to produce the design selected. Some designs
require only one knot at the bottom. It is best to make a rough
sketch of the design on paper. This will greatly aid the maker in
carrying on the work.

When the main part of the screen is finished, the cross cords,
used for spacing and binding the whole together, are put in place.
This is done with a needle made from a piece of small wire, as
shown in Fig. 4. The cross cords are woven in as shown in Fig. 5.
As many of these cross cords can be put in as desired, and if
placed from 6 to 12 in. apart, a solid screen will be made instead
of a portiere. The twisted cross cords should be of such material,
and put through in such manner that they will not be readily seen.
If paper beads are used they can be colored to suit and hardened
by varnishing. The first design shown is for using bamboo. The
cords are knotted to hold the bamboo pieces in place. The finished
portiere will resemble drawn work in cloth. Many beautiful
hangings can be easily fashioned.

The second design is to be constructed with a plain ground of
either straw, bamboo or rolled paper. The cords are hung upon a
round stick with rings of metal to make the sliding easy. The
design is made by stringing beads of colored glass at the right
places between the lengths of ground material. One bead is placed
at the extreme end of each cord. The rows of twisted cord placed
at the top keep the strings properly spaced.
--Contributed by Geo. M. Harrer, Lockport, New York.



** Makeshift Camper's Lantern [266]

While out camping, our only lantern was accidentally smashed
beyond repair, and it was necessary to devise something that would
take its place.

[Illustration: Lantern Made of Old Cans]

We took an empty tomato can and cut out the tin, 3 in. wide, for a
length extending from a point 2 in. below the top to within 1/4
in. of the bottom. Each side of the cut-out A was bent inward in
the shape of a letter S, in which was placed a piece of glass.
Four V-shaped notches were cut, as shown at B, near the top of the
can and their points turned outward. A slit was cut in the bottom,
shaped as shown at C, and the pointed ends thus formed were turned
up to make a place for holding the base of a candle. A larger can
was secured and the bottom perforated. This was turned over the
top of the other can. A heavy wire was run through the
perforations and a short piece of broom handle used to make a
bail.
--Contributed by Maurice Baudier, New Orleans, La.



** New Tires for Carpet-Sweeper Wheels [266]

The rubber tires on carpet-sweeper wheels often become so badly
worn and streched that they fail to grip the carpet firmly enough
to run the sweeper. To remedy this, procure some rubber tape a
little wider than the rims of the old wheels, remove the old
rubber tires and wind the tape on the rims to the proper
thickness. Trim the edges with a sharp knife and rub on some chalk
or soapstone powder to prevent the tape from sticking to the
carpet. A sweeper treated in this manner will work as well as a
new one.
--Contributed by W. H. Shay, Newburgh, N. Y.



** Gauntlets on Gloves [266]

When the fingers or palms of gloves with gauntlets wear out, do
not throw away the gloves, but cut off the gauntlets and procure a
pair of gloves with short wrists to which the old gauntlets can be
sewn after the wrist bands have been removed from the new gloves.
The sewing may be done either by hand or on a machine, gathering
in any fullness in the bellows of the cuff on the under side. A
pair of gauntlets will outwear three or four pairs of gloves.
--Contributed by Joseph H. Sanford, Pasadena, Cal.



** How to Make an Ornamental Brass Flag [266]

The outlines of the flag--which may be of any size to suit the
metal at hand--and the name are first drawn on a sheet of thin
paper and then transferred to the brass by tracing through a sheet
of carbon paper. The brass should be somewhat larger than the
design.

The brass is fastened to a block of soft wood with small nails
driven through the edges. Indent the name and outline of the flag
with a small chisel with the face ground flat, about 1/16 in.
wide. This should be done gradually, sinking the lines deeper and
deeper by going over them a number of times. After this is
finished, the brass is loosened from the block, turned over but
not fastened, and the whole outside of and between the letters is
indented with the rounded end of a nail, giving the appearance of
hammered brass.

The edges are now cut off and four holes drilled, two for the
chain by which to hang the flag to the wall, and two along the
side for attaching the staff. The staff is a small brass rod with
a knob attached to the top end.

It would be well to polish the brass at first, if the finished
work is to be

[Illustration: The Finished Flag]

bright, as it cannot be done after the flag is completed. A coat
of lacquer is applied to keep it from tarnishing. This is done by
heating the brass and quickly applying a coat of shellac.
--Contributed by Chas. Schaffner, Maywood, Ill.



** An Adjustable Punching-Bag Platform [267]

A punching-bag platform, suitable for the tall athlete as well as
the small boy, is shown in the accompanying sketch. The platform
is securely fastened to two strong wooden arms or braces, which in
turn are nailed to a 2 by 12-in. plank as long as the diameter of
the platform. This plank, as shown in the small drawing at the
upper left-hand corner of the sketch, is placed in grooves or
slots fastened against the side of a wall. The plank with the
platform attached may be raised or lowered to the desired height
and held there by a pin or bolt put through the bolt-hole of the
plank and into a hole in the wall.
--Contributed by W. A. Jaquythe, Richmond, Cal.

[Illustration: Adjustable Platform]



** Clasp for Holding Flexible Lamp Cords [267]

A very easily made drop-light adjuster is shown in the
illustration. It consists of a piece of copper wire 7/8 in. in
diameter, bent as shown. This clasp is capable of standing a
strong pull and will hold the lamp and socket with a glass shade.
--E. K. Marshall, Oak Park, Ill.

[Illustration: Clasp]



** Protect Camel Hair Brushes [267]

Camel hair brushes for painters' use should never be allowed to
come in contact with water.



** Home-Made Electric Clock [268]

The clock illustrated herewith is driven by means of
electromagnets acting directly on the pendulum bob. Unlike most
clocks, the pendulum swings

[Illustration: Magnetic Clock]

forward and backward instead of laterally. The construction is
very simple, and the result is not only novel but well worth
while, because one does not have to bother about winding a clock,
such as this one, says the Scientific American.

The clock is mounted on a wooden base measuring 3-3/4 by6-1/2 in.,
by 1-5/16 in. thick. Secured centrally on this base is a 1/8 by
3/4-in. bar, 6 in. long and at each side of this, 5/16 in. away,
is an electromagnet, 3/4 in. in diameter and 1-7/16 in. high. Two
uprights, 7-1/2 in. high and 1/4 in. in diameter, are secured in
the base bar, and are connected at the top by a brass yoke piece
on which the clock frame is supported. Just below the yoke piece a
hole is drilled in each upright to receive the pivot pins of the
crosspiece secured to the upper end of the pendulum rod. The
pendulum bob at the lower end is adjusted to swing just clear of
the electromagnets. Mounted at the right-hand side of the base are
three tall binding-posts, the center one being 2-3/4 in. high, and
the other two 2-5/8 in. high. Each is fitted with a piece of
copper wire provided with a small brass spring tip. These springs
lie in the plane of the pendulum, which serves to swing the
central tip first against one and then against the other of the
side tips, thereby closing the circuit of first one magnet and
then the other. Each magnet attracts the pendulum until its
circuit is broken by release of the center tip, and on the return
swing of the pendulum the circuit of the other magnet is similarly
closed. Thus the pendulum is kept in motion by the alternate
magnetic impulses. The clock train is taken from a standard clock
and the motion of the pendulum is imparted to the escape wheel by
means of a pawl, bearing on the latter, which is lifted at each
forward stroke of the pendulum by an arm projecting forward from
the pivotal end of the pendulum rod.



** Method of Joining Boards [268]

The amateur wood-worker often has trouble in joining two boards
together so that they will fit square and tight. The accompanying
sketch shows a simple and effective method of doing this. Secure a
board, A, about 12 in. wide that is perfectly flat. Fasten another
board, B, about 6 in. wide, to the first one with screws or glue.
Now place the board to be joined, C, on the board B, letting it
extend over the inside edge about 1 in. and fastening it to the
others with clamps at each end. Lay the plane on its side and
plane the edge straight. Place the second board in the clamps in
the same manner as the first, only have the opposite side up. If
the cutting edge of the blade is not vertical, the boards planed
in this manner will fit as shown in the upper sketch. In using
this method, first-class joints can be made without much trouble.
--Contributed by V. Metzech, Chicago.

[Illustration: Joining Boards]



** Toy Gun for Throwing Cardboard Squares [269]

The parts of the gun are attached to a thin piece of wood 1 in.
wide and 5 in. long. It is best to use a piece of wood cut from
the side or cover of a cigar box. A rectangular hole 3/16 in. wide
and 1 in. long is cut in the wood longitudinally along its axis
and 1-3/8 in. from one end, as shown at A, Fig. 1. A small notch
is made with the point of a knife blade at B and notches are cut
in the end of the wood as shown at C. Rubber bands are fastened in
these notches as shown in Fig. 2. The trigger, whose dimensions
are given in Fig. 3, is fastened in the hole A, Fig. 1, by driving
a pin through the wood. The assembled parts are shown in Fig. 4.

Place the cardboard square in the nick B, attach the rubber bands
and pull the trigger. The top rubber band will fly off and drive
the cardboard

[Illustration: Details of Toy Gun]

square 75 ft. or more. The cardboard should be about 1/2 in.
square. These can be cut from any old pasteboard box.
--Contributed by Elmer A. Vanderslice, Phoenixville, Pa.



** Photographic Developing Tray [269]

Plates developed in an ordinary tray must be removed from the bath
occasionally for examination. The film when in a chemical-soaked
condition is easily damaged. The tray illustrated herewith was
made for the purpose of developing plates without having to take
hold of them until the bath had completed its work, the
examination being made through the plate and the bottom of the
tray.

A pocket is provided for the liquid developer in one end of the
tray when it

[Illustration: Developing Tray with Glass Bottom]

is turned up in a vertical position. A tray for developing 5 by
7-in. plates should be made 8 in. square inside. The side pieces
with the grooves for the glass are shown in Fig. 1. Two of each of
these pieces are made with mitered ends. The short groove shown in
the top piece of the illustration is for inserting the plate
covering on the pocket end of the tray.

Two blocks, one-half the length of the side pieces, are put in
between the glass plates to hold the plate being developed from
dropping down when the tray is tipped up in a vertical position.
The glass bottom of the tray is 8-1/2 in. square, which allows 1/4
in. on all edges to set in the grooves of the side pieces. The
wood pieces should be well soaked in hot paraffin, and the mitered
corners well glued and nailed.
--Contributed by J.A. Simonis, Fostoria, Ohio.



** Iron Putty [269]

A good filler used as a putty on iron castings may be made as
follows: Take, by weight, 3 parts of stiff keg lead, 5 parts of
black filler, 2 parts of whiting, 5 parts of pulverized silica and
make into a paste with a mixture of one part each of coach japan,
rubbing varnish and turpentine.



** Rubber Bands in Kite Balancing Strings [270]

Kite flyers will find it to their advantage to place rubber bands
of

[Illustration: Bands in String]

suitable size in the balancing strings to the kite, as shown in
the illustration. This will prevent a "break-away" and also make
the right pull, if only two bands are put in the lower strings.
--Contributed by Thos. DeLoof, Grand Rapids, Michigan.



** An Aid in Sketching [270]

Sketching requires some little training, but with the apparatus
here illustrated an inexperienced person can obtain excellent
results. The apparatus is made of a box 8 in. deep, 8 in. wide and
about 1 ft. long. A double convex lens, G, is fitted in a brass
tube which should have a sliding fit in another shorter and larger
tube fastened to the end of the box. A mirror, II, is set at an
angle of 45 deg.

[Illustration: Sketching Aid]

in the opposite end of the box. This reflects the rays of light
passing through the lens to the surface K, which may be either of
ground or plain glass. The lid or cover EF protects the glass and
keeps the strong light out when sketching. The inside of the box
and brass tube are painted a dull black.

In use, the device is set with the lens tube directed toward the
scene to be painted or sketched and the lens focused so the
reflected picture will be seen in sharp detail on the glass.
Select your colors and put them on the respective colors depicted
on the glass. If you wish to make a pencil drawing, all you have
to do is to fill in the lines in the picture on the ground glass.
If a plain glass is used, place tracing paper on its surface, and
the picture can be drawn as described.



** How to Make Miniature Electric Lamp Sockets [270]

A socket for a miniature lamp can be made as shown in the sketch.
A brass spring wire is wound around the base of the threads on the
lamp and an eye turned on each end to receive a screw and a
binding-post, as shown in Fig. 1. A piece of metal, preferably
copper, is attached to a wood base as shown in Fig. 2 and the
coil-spring socket fastened across it in the opposite direction.
Bend the wire so that the spring presses the lamp against the
metal. If the wire fits the lamp loosely, remove the lamp and
press the sides of the coil closer together. The metal parts can

[Illustration: Wire Socket]

be attached to any smooth surface of wood without making a regular
base.
--Contributed by Abner B. Shaw, No. Dartmouth, Mass.



** Imitation Arms and Armor-Part V [271]

The preceding chapters gave descriptions of making arms in
imitation of ancient weapons, and now the amateur armorer must
have some helmets to add to his collection. There is no limit to
the size of the helmet, and it may be made as a model or full
sized. In constructing helmets, a mass of clay of any kind that is
easily workable and fairly stiff, is necessary, says the English
Mechanic, London. It must be kept moist and well kneaded. A large

[Illustration: Making the Clay Model and Three Helmet Designs]

Board or several planks, joined closely together, on which to
place the clay, will be necessary. The size of this board will
depend on the size of the work that is intended to be modeled upon
it.

The way to make a helmet is described in the following method of
producing a German morion, shown in Fig. 1. This helmet has
fleur-de-lis in embossed work, and on each side is a badge of the
civic regiment of the city of Munich. The side view of the helmet
is shown in Fig. 1.

The clay, is put on the board and modeled into the shape shown in
Fig. 2. This is done with the aid of a pair of compasses, a few
clay-modeling tools, and the deft use of the fingers. The
fleur-de-lis are slightly raised, as in bas-relief. To aid in
getting the helmet in correct proportion on both sides, and over
the crest on top, cut out the shape from a piece of wood, as shown
in Fig. 3, with a keyhole saw. This wood being passed carefully
and firmly over the clay will bring it into shape, and will also
show where there may be any deficiencies in the modeling, which
can then be easily remedied by adding more clay. The cut-out
pattern shown in Fig. 4 is the side outline of the helmet.

Scraps of thin, brown, wrapping paper are put to soak in a basin
of water to which has been added about a tablespoonful of size
melted and well stirred, or some thin glue, and left over night to
soak. The paper should be torn in irregular shapes about as large
as the palm of the hand. After the clay model is finished, give it
a thin coat of oil-sweet or olive oil will answer the purpose very
well. All being ready, the clay model oiled, and the basin of
soaked paper near to hand, take, up one piece of paper at a time
and very carefully place it upon the model, pressing it well on
the clay and into and around any crevices and patterns, and
continue until the clay is completely covered.

This being done, give the paper a thin and even coating of glue,
which must be quite hot and put on as quickly

[Illustration: Ancient Helmets]

as possible. Put on a second layer of paper as carefully as
before, then another coating of glue, and so on, until there are
from four to six coats of glue and paper. When dry, the paper
coating should be quite stout and strong enough for the helmet to
be used for ornamental purposes. Before taking it off the model,
which should be no difficult matter, owing to the clay being
oiled, trim off any ragged edges of paper with a sharp knife, and
smooth and finish all over with some fine sandpaper. The paper is
then given a thin coat of glue and sections of tinfoil stuck on to
give it a finished appearance. When the helmet is off the model,
make holes with a small awl at equal distances, through which to
insert some fancy brass nails, bending the points over and flat
against the inside of the helmet.

A vizor helmet is shown in Fig. 5. This helmet has a movable vizor
in the front that can be lifted up, a crest on top, and around the
neck a narrow gorget which rests upon the wearer's shoulders. The
whole helmet with the exception of the vizor, should be modeled
and made in one piece. The vizor can then be made and put in place
with a brass-headed nail on each side. The oblong slits in front
of the vizor must be carefully marked out with a pencil and cut
through with a knife or chisel.

In Fig. 6 is shown an Italian casque of a foot soldier of the
sixteenth century. This helmet may have the appearance of being
richly engraved as shown in one-half of the drawing, or, a few
lines running down, as seen in the other part of the sketch, will
make it look neat. The band is decorated with brass studs.

An Italian cabasset of the sixteenth century is shown in Fig. 7.
This helmet is elaborately decorated with fancy and round-headed
nails, as shown: in the design.

In Fig. 8 is shown a large bassinet with a hinged vizor which
comes very much forward, so as to allow the wearer to breathe
freely. This helmet was worn about the sixteenth century, and was
probably used for tilting and tournaments.

A burgonet skull-cap of the seventeenth century is shown in Fig.
9. The vizor is composed of a single bar of metal, square in
shape, which slides up and down in an iron socket attached to the
front of the helmet, and is held in any position by a thumbscrew
as shown in the illustration.

A hole in the peak of the helmet allows it to hang in front of the
wearer's face. This contrivance should be made of wood, the helmet
to be modeled in three pieces, the skullcap, peak and lobster
shell neck guard in one piece, and the ear guards in two pieces,
one for each side. The center of the ear guards are perforated.
All of the helmets are made in the same manner as described for
Fig. 1. They are all covered with tinfoil.



** How to Repair Linoleum [273]

A deep crack or fissure right in front of the kitchen cabinet
spoiled the appearance of the new linoleum. The damaged spot was
removed with a sharp knife and from a left-over scrap a piece was
cut of the same outline and size. The edges were varnished and
then the patch was set in the open space. The linoleum was given a
good coat of varnish making it more durable. When perfectly dry,
the piecing could not be detected.
--Contributed by Paul Keller, Indianapolis, Indiana.



** How to Make an Electric Stove [273]

The parts necessary for making an electric stove are: Two metal
pie plates of the same size; 4 lb. of fire clay; two ordinary
binding posts; about 1 lb. of mineral wool, or, if this cannot be
obtained, thick sheet asbestos; one oblong piece of wood, 1 in.
thick, 12 in. wide and 15 in. long; one small switch; one fuse
block; about 80 ft. of No. 22 gauge resistance wire, German-silver
wire is better, as it stands a higher temperature; two
middle-sized stove bolts with nuts; one glass tube, about 1/4 in.
in diameter and 9 in. long, which can be bought from a local
druggist, and two large 3-in. screws.

If a neat appearance is desired, the wood can be thoroughly
sandpapered on one side and the corners and edges rounded off on
the upper side. Punch holes in one of the pie plates, as shown in
Fig. 1. The two holes, E and F, are on the rim and should be
exactly on a line with the hole D punched in the center. The holes
B and C are about 3 in. apart and should be at equal distances
from the center hole D. The rim of the second plate is drilled to
make two holes, AA, Fig. 2, that will match the holes E and F in
the first plate, Fig. 1. A round collar of galvanized iron, FF,
Fig. 4, 3 in. high, is made with a diameter to receive the first
plate snugly. Two small flaps are cut and turned out and holes
punched in their centers, AA, to receive screws for holding it to
the base. Two bolts are soldered in the holes E and F, Fig. 1, and
used to hold the

[Illustration: Details of Electric Stove]

rims of both plates together, when they are placed in opposite
positions, as shown in Fig. 4. This will make an open space
between the plates. The collar is then screwed to one end of the
base, as shown in Fig. 2.

Two holes are bored through the base to correspond with the holes
D and A in the bottom plate. The glass tube is cut to make two
pieces, each 4-1/2 in. long. This can be done easily by filing a
nick in the tube at the proper point and breaking it. These tubes
are forced into the holes bored in the base, and, if the
measurements are correct, should extend about 1/4 in. above the
collar. The mineral wool, JJ, Fig. 4, is then packed down inside
the collar, until it is within 1 in. of the top. This will allow
the plate, Fig. 1, to rest on the wool and the ends of the glass
tubes, GG, Fig. 4, to project through the holes D and A of the
plate, Fig. 1. The rim of the plate should be level with the top
edge of the collar. If asbestos is used, the sheets should be cut
into disks having the same diameter as the inside of the collar,
and holes cut to coincide with the holes D and A of the plate. The
small scraps should be dampened and made into pulp to fill the
space H, Fig. 4. The plate, Fig. 1, is held to the base by two
screws which are run through the holes BC and take the position
shown by DD, Fig. 4.

The two binding-posts are attached on the base at D, Fig. 2, also
the switch B and the fuse block C, holes being bored in the base
to make the wire connections. The reverse side of the base, with
slits cut for the wires, is shown in Fig. 3. The points marked BB
are the glass tubes; AA, the holes leading to the switch; and C,
the fuse block. The wires run through the glass tubes GG, Fig. 4,
are allowed to project about 1 in. for connections.

The best way to find the correct length of the resistance wire is
to take a large clay or drain tile and wind the wire tightly
around it, allowing a space between each turn. The tile is then
set on its side with a block or brick under each end. It should
not be set on end, as the turns of the wires, when heated, will
slip and come in contact with each other, causing a short circuit.
When the tile is in place, a short piece of fuse wire is fastened
to each of its two ends. A 5-ampere fuse wire is about strong
enough. A connection is made to these two wires from an
electric-light socket. The wire will get hot but probably remain
the same color. If this is the case, one of the feed wires is
disconnected from the fuse wire and gradually moved farther down
the coil until a point is found where the resistance wire glows a
dull red. This point marks the proper length to cut it, as the
wire should not be allowed to become any hotter. If the wire gets
bright hot when the current is turned on, more wire should be
added. The wire is then made into a long coil by winding it around
a large wire nail. The coils should be open and about 1/8 in.
apart.

Next, the fire clay is moistened and well mixed, using care not to
get it too wet. It should have the proper consistency to mould
well. The clay, II, Fig. 4, is then packed in the first plate to a
height of about 1/4 in. above the rim. While the clay is damp, one
end of the coil is connected with the wire in the central glass
tube, and the coil laid in a spiral winding on the damp clay, KK,
and pressed into it. When this is done, the other end is connected
to the wire projecting from the outer glass tube. As these
connections cannot be soldered, the ends of the wires should be
twisted closely together, so that the circuit will not become
broken. Make sure that the coils of wire do not touch each other
or the top plate. The fuse wire (about 5 amperes) is put into the
fuse block, and wires with a socket adapter connected to the two
binding-posts. The top plate is put in place and screwed down.
This completes the stove.

It should be set aside in a warm place for a few days to dry out
the packing. If it is not thoroughly dry, steam will form when the
current is applied. It should not be left heated in this
condition. The top plate is used when cooking and removed when
making toast.
--Contributed by R. H. Cnonyn, St. Catherines, Can.



** How to Make Weights for Athletes [274]

Many times boys would like to make their own shots and weights for

[Illustration: Mold for the Lead]

athletic stunts, but do not know how to go about it to cast the
metal. In making a lead sphere as shown in the illustration, it is
not necessary to know the method of molding. The round lead weight
for shot-putting or hammer throwing can be cast in a hollow
cardboard or pressed-paper ball, sold in department and toy stores
for 10 cents. Cut a 1/2-in. hole in the ball as shown in Fig. 1
and place it with the hole up in damp sand and press or tamp the
sand lightly around the ball as shown in the section, Fig. 2.
Cover over about 1 in. deep. A wood plug inserted in the hole will
prevent any sand falling inside. When the sand is tamped in and
the plug removed, it leaves a gate for the metal. Pour melted lead
into the gate until it is full, then, when cool, shake it out from
the sand and remove the charred paper. A file can be used to
remove any rough places. The dry paper ball prevents any
sputtering of the hot lead.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Removing Pies from Pans [275]

Sometimes the juices from a hot pie make it stick to the pan so
tightly that a knife blade must be run under to cut it loose. If a
knife with a flexible blade is not used, the pie will be damaged.

[Illustration: Separating Pies from Pans]

If the pie pans are provided with the simple attachment shown in
the accompanying sketch, the baked dough can be separated from the
tin with one revolution of the cutter. The cutter is made from a
piece of heavy tin, bent to the same outline as the inside of the
pan and pivoted at its center.



** Stretcher for Drying Photograph Prints [275]

A quick and convenient way to dry prints is to place them on a
cheesecloth stretcher. Such a stretcher can be made on a light
wood frame, constructed of 3/4-in. square material in any size,
but 12 by 24 in. is large enough. The end pieces B are fastened on
top of the long side pieces A, and the cheesecloth C stretched and
tacked over them, as shown.

The prints should be placed face up on the cloth, and the frame
set near a window. If the stretcher is made in

[Illustration: Cloth on the Frame]

this way, the air can enter from both top and bottom, and the
prints will dry rapidly. Several of these frames can be stacked
and a large number of prints thus dried at the same time.
--Contributed by Andrew G. Thorne, Louisville, Ky.



** A Temporary Funnel [275]

The amateur photographer often has some solution which he desires
to put into a bottle which his glass funnel will not fit, says the
Photographic Times. The funnel made by rolling up a piece of paper
usually allows half of the solution to run down the outside of the
bottle, thereby causing the amateur to be dubbed a "musser," A
better way is to take an ordinary envelope and cut it off as shown
by the dotted lines. Then clip a little off the

[Illustration: Paper Funnel]

point, open out, and you have a funnel that will not give any
trouble. It is cheap and you can afford to throw it away when
dirty, thereby saving time and washing.



** An Electric Engine [276]

The parts of this engine are supported on a base 3/4 in. thick, 4
in. wide and 7 in. long. The upright B, Fig. 1,

[Illustration: Shaft Turned by Magnetism]

which is 1/2 in. thick and 3 in. high, is secured across the base
about one-third of the distance from one end and fastened with a
wood screw put through from the under side. The magnet core C is
made of a carriage bolt, 2-1/2 in. long, which is fastened in a
hole in the top part of the upright B so that the end C will
protrude slightly. Before placing the bolt in the hole of the
upright, slip on two cardboard washers, each 1 in. in diameter,
one at the head end and the other against the upright B. Wrap a
thin piece of paper around the bolt between the washers and wind
the space full of No. 22 gauge magnet wire, allowing each end to
project for connections.

The driving arm D, Figs. 1 and 3, is made of a piece of soft sheet
iron, 1/2 in. wide and 3 in. long. A small block is fastened to
the lower end of the metal and pivoted between two uprights, 1/2
in. high, which are fastened to the base. The uprights on each
side of the block are better shown in Fig. 3.

Two supports, each 1/2 in. thick and 3 in. high, are fastened with
screws about half way between the end of the base and the upright
B, Fig. 1. The end view of these supports is shown in Fig. 2, at
GG. A 1/8-in. hole is bored through the top part of each support
so they will be in a line for the axle. The axle is made of a
piece of steel 1/8 in. in diameter and about 4 in. long. An offset
is bent in the center, as shown, for the crank. A small flywheel
is attached to one end of the shaft. The connecting rod E, Fig. 1,
is made of wood and fastened to the upper end of the driving arm D
with a small screw or nail. The contact F is made of a strip of
copper, 14 in. wide. This is to open and close the circuit when
the engine is running. The connections are made as shown in Fig.
1.

Connect two dry cells to the binding-posts and turn the flywheel.
The current passing through the magnet pulls the driving arm
toward the bolt head, which gives the shaft a half turn. The
turning of the shaft pulls the arm away from the copper piece F,
causing a break in the current. As the shaft revolves, the arm is
again brought back against the copper strip F, thus the current is
broken and applied at each revolution of the shaft. --Contributed
by S. W. Herron, Le Mars, Iowa.



** Child's Home-Made Swing Seat [276]

A very useful swing or seat for children can be made from a box or
packing case. Procure a box of the right size and saw it out in
the shape shown in the illustration. The apron or board in front
slides on the two front ropes. The board can be raised to place
the

[Illustration: Made of a Box]

child in the box and to remove him. The ropes are fastened to the
box by tying knots in their ends and driving staples over them.



** Clay Flower Pots Used for Bird Houses [277]

A novel use of the common garden flower pot may be made by
enlarging the small opening at the bottom with a pair of pliers,
and carefully breaking the clay away until the opening is large
enough to admit a small bird.

Place the pot, bottom side up, on a board, 3 in. wider than the
diameter of the largest pot used, and fasten it to the board with
wood cleats and brass screws. Fit the cleats as close as possible
to the sides of the pot. One or more pots may be used, as shown in
the sketch.

The board on which the pots are fastened is nailed or screwed to a
post or pole 10 or 12 ft. in height. The board is braced with lath
or similar strips of wood, making a framework suitable for a
roost. In designing the roost, the lath can be arranged to make it
quite attractive, or the braces may be of twigs and branches of a
tree to make a rustic effect.
--Contributed by William F. Stecher, Dorchester, Mass.

[Illustration: Pots Fastened to the Board]



** Location of a Gas Meter [277]

The gas meter should not be located in a warm place or the gas
will expand before the meter measures it and the gas bill will be
proportionately increased. Gas expands by about 1/491 part of its
volume for each deg. F. that it is heated. If the meter is warmed
10 deg. F., it will make the gas cost over 2 per cent more,
without any corresponding benefit.



** How to Make Rope Grills [277]

Beautiful and useful household ornaments, grills and gratings for
doors, windows, shelves, odd corners, etc., can be made by the
following method at a slight cost and by anyone possessing a
little ingenuity. The materials required are rope or, preferably,
common window cord (called sash cord) about 5/16 in. in diameter;
ordinary glue, paraffin and paint or varnish. A few strips of wood
or molding are very handy to use around the edges.

The design must be considered first and when one is selected, if
it is other than straight lines, adopt the method described.

Take a smooth flat board and layout the design or designs which,
when combined, will produce the pattern desired. Drive finishing
nails at the angle points or along curves as required. Coat the
board along the lines of the patterns with melted paraffin, using
an ordinary painter's brush to prevent the ropes from sticking to
the boards after they are soaked in glue and run around the nails.

Soak the sash cord in common glue sizing for a short time, then
bend or twist it along or around the lines desired, as shown in
Fig. 1, and give it time to dry. The bottom part of the sketch,
Fig. 1, shows a method of winding the rope on a round stick to
make circular objects. Wind the

[Illustration: Fig. 2-Designs for Grills]

desired number of turns and when dry, cut and glue them together.

[Illustration: Fig. 1-Method of Forming the Rope]

In Fig. 2, six designs are shown. These suggest ideas in making up
combinations or in plain figures and the number is limited only by
the ingenuity of the designer.
--Contributed by Geo. M. Harrer, Lockport, N. Y.



** A Simple and Effective Filter [278]

Procure an ordinary lamp chimney and fit two or three thicknesses
of cheese cloth over the end of it. Press a tuft of absorbent
cotton into the small part of the neck to a depth of about 3 in.
Insert the chimney in a hole cut in a wood shelf used as a
support. Pour the water in until the filter is filled, when it
will be observed that any organic matter, chips of iron rust,
etc., will be retained by the cotton. The fine organic matter may
penetrate the cotton for about 1 in., but no farther. The
resultant filtered water will be clear and pure.

[Illustration: Filter]



** Cutting Tools [278]

The cutting point of a tool should never be below the centers.



** Imitation Arms and Armor-Part VI [279]

A mass of any kind of clay that is easily modeled and fairly stiff
must be prepared and kept moist and well kneaded for making the
models over which paper is formed to make the shape of the
articles illustrated in these sketches. A modeling board must be
made of one large board or several pieces joined closely together
upon which to work the clay, says the English Mechanic, London.
The size of the board depends upon the size of the work to be
made.

[Illustration: Armor and Clay Models]

An open chamfron of the fifteenth century is shown in Fig. 1. This
piece of horse armor, which was used in front of a horse's head,
makes a splendid center for a shield on which are fixed the
swords, etc., and is a good piece for the amateur armorer to try
his hand on in the way of modeling in clay or papier mache work.
The opening for the animal to put his head into is semicircular,
and the sides do not cover the jaws. As the main part of this
armor is worn in front of the head the extreme depth is about 4
in. The entire head piece must be modeled in clay with the hands,
after which it is covered with a thin and even coating of sweet or
pure olive oil. A day before making the clay model some pieces of
thin, brown wrapping paper are torn in irregular shapes to the,
size of the palm of the hand and put to soak in a basin of water
in which a tablespoonful of size has been dissolved. If size
cannot be obtained from your local painter, a weak solution of
glue will do equally well. All being ready, and the clay model
oiled, take up one piece of paper at a time and very carefully
place it on the surface of the model, pressing it on well and into
and around any crevices and patterns. Continue this operation
until the clay model is completely covered on every part. This
being done, give the paper a thin and even coating of glue, which
must be quite hot and laid on as quickly as possible. Lay on a
second layer of paper as carefully as before, then another coat of
glue, and so on until there are five or six coats of glue and
paper. When this is dry it will be strong enough for all
ornamental purposes. The ragged edges of the paper are trimmed off
with a sharp knife and the whole surface smoothed with fine
sandpaper. Then carefully glue on sections of tinfoil to give the
armor the appearance of steel. The armor is now removed from the
model.

A mitten gauntlet of the fifteenth century is shown in Fig. 2.
This can be made in one piece, with the exception of the thumb
shield, which is separate. The thumb shield is attached to the
thumb of an old glove which is fastened with round headed nails on
the inside of the gauntlet.

[Illustration: Corrugated Breastplate and Former]

The part covering the wrist is a circular piece, but the back is
not necessary, as it would not be seen when the gauntlet is
hanging in its place.

In Fig. 3 is shown a gauntlet of the seventeenth century with
separately articulated fingers. This gauntlet may be molded in one
piece, except the thumb and fingers, which must be made separately
and fastened with the thumb shield to the leather glove that is
attached to the inside of the gauntlet, the same as in Fig. 2.

A breastplate and tassets of the sixteenth century are shown in
Fig. 4. The tassets are separate and attached to the front plate
with straps and buckles, as shown in the sketch. There is a belt
around the waist which helps to hold the back plate on. Attached
to the back of the plate would be two short straps at the
shoulder. These are passed through the buckles shown at the top
right and left-hand corners of the front plate. For decorative
purposes the back plate need not be made, and therefore it is not
described. The method of making armor is the same as of making
helmets, but as larger pieces are formed it is well to use less
clay owing to the bulk and weight.

An arrangement is shown in Fig. 5 to reduce the amount of clay
used. This triangular-shaped support, which can be made in any
size, is placed on the modeling board or bench and covered with
clay. This will make the model light and easy to move around, and
will require less clay. It is not necessary to have smooth boards;
the rougher the better, as the surface will hold the clay. The
clay forms modeled up ready to receive the patches of brown paper
on the surface are shown in Figs. 6 and 7.

A German fluted armor used at the beginning of the sixteenth
century is shown in Fig. 8. The breastplate and tassets of this
armor are supposed to be in one piece, but for convenience in
making it will be found best to make them separately and then glue
them together after they are taken from the model. A narrow
leather belt placed around the armor will cover the joint. Fluted
armor takes its name from a series of corrugated grooves, 1/2 in.
in depth, running down the plate. A piece of board, cut into the
shape shown in Fig. 9, will be very useful for marking out the
fluted lines.



** Home-Made Hand Vise [280]

A vise for holding small articles while filing can be made as
shown in the illustration. The vise consists of three pieces of
wood, two for the jaws and one a wedge. The hinge for connecting
the two jaws is made of four small screw eyes, two in each jaw.
When locating the place for the screw eyes, place the two in one
jaw so they will fit between the two of the other jaw. Put a nail
through the eyes when the jaws are matched together and they are
ready for the wedge in clamping the article to be filed.
--Contributed by John G. Buxton, Redondo Beach, Calif.

[Illustration: Hand Vise]



** Detector for Slight Electrical Charges [281]

A thin glass bottle is thoroughly cleaned and fitted with a rubber
stopper. A hole is made through the center of the stopper large
enough to admit a small brass rod. The length of this rod will be
governed by the shape of the bottle, but 3-1/2 in. will be about
right. The bottom of the rod is bent and two pieces of aluminum
foil, each about 1/4 in. wide and 1/2 in. long, are glued to it.
The two pieces of foil, fastened to the rod, are better shown in
Fig. 2. Fasten a polished brass ball to, the top of the rod, and
the instrument is ready for use. Place the article which you wish
to test near the ball, and if it holds a

[Illustration: Aluminum Foil in a Bottle]

slight electrical charge, the two pieces of foil will draw
together. If it does not hold a charge, the foils will not move.
--Contributed by Ralph L. La Rue, Goshen, N. Y.



** Fishing through Ice with a Tip-Up [281]

The tip-up, used for signaling the fisherman when a fish is
caught, is made of a 1/4-in. pine board, about 15 in. long, 2-1/2
in. wide at one end and narrowing down to about 1 in at the other.
At a point 6 in. from the smaller end, the board should be cut
slightly wider and a 1/2-in. hole bored through it. Two or three
wrappings of fine copper wire may be wound around the board on
each side

[Illustration: Tip-Up in Place]

of the hole to give added strength. Both ends of the board should
be notched deeply.

A long gash is cut in the ice and then a round hole is made with a
chisel, as this will cut under the water without splashing. The
chipped ice can be removed with a pail. A rod or round stick of
wood is passed through the hole in the tip-up and placed across
the round hole, as shown in the illustration.

The fishhook is baited in the usual way and hung on a line from
the short end of the tip-up. When a fish is hooked, the other end
will tip up and signal the fisherman. Any number of holes can be
cut in the ice and a tip-up used in each, thus enabling one person
to take care of as many lines.



** Home-Made Candle Holder [281]

The candlestick or holder shown in the illustration is made of an
ordinary tin can, such as is used for canning salmon or potted
ham. Three triangular cuts are made in the cover or bottom of the
can and the points turned up about the can die. The can may be
bronzed, silvered, enameled or otherwise decorated, thus making it
ornamental as well as useful.
--Contributed by Mrs. A. M. Bryan, Corsicana, Texas.



** How to Make a Match Holder of Wood and Metal [282]

A very simple piece of art craft work is easily made, as follows:
Secure a piece of paper and upon it draw the outline and design,
as indicated in the

[Illustration: Match Holder]

accompanying sketch. The size may be made to suit the taste of the
worker. A good size is 5 in. wide by 6 in. long over all. The
metal holder should be proportioned to this size, as shown.

Having completed the drawing, take a piece of thin wood, 3/8 or
1/4 in. thick, and trace upon it the design and outline, using a
piece of carbon paper. A couple of thumb tacks should be used to
fasten the paper and design in place. Put the tacks in the lines
of the design so that the holes will not show in the finished
piece. Any kind of wood will do. Basswood or butternut, or even
pine, will do as well as the more expensive woods.

Next prepare the metal holder. This may be made of brass or copper
and need not be of very heavy gauge-No. 22 is plenty heavy enough.
The easiest way to get the shape of the metal is to make a paper
pattern of the development. The illustration shows how this will
look and the size of the parts for the back dimensioned above.
Trace this shape on the metal with the carbon paper and cut it out
by means of metal shears. Polish the metal, using powdered pumice
and lye, then with a nail, punch the holes, through which small
round-head brass screws are to be placed to hold the metal to the
wood back. Carefully bend the metal to shape by placing it on the
edge of a board and putting another board on top and over the
lower edge so as to keep the bending true.

The wood back may be treated in quite a variety of ways. If soft
wood, such as basswood or pine was used, it may be treated by
burning with the pyrography outfit. If no outfit is at hand a very
satisfactory way is to take a knife and cut a very small V-shaped
groove around the design and border so as to keep the colors from
"running." Next stain the leaves of the conventional plant with a
little green wood dye and with another dye stain the petals of the
flower red. Malachite and mahogany are the colors to use. Rub a
coat of weathered oil stain over the whole back and wipe dry with
a cloth. The green and red are barbarously brilliant when first
put on, but by covering them at the same time the background is
colored brown, they are "greyed" in a most pleasing manner. When
it has dried over night, put a coat or two of wax and polish over
the wood as the directions on the can suggest.

The metal holder may next be fastened in place.

If one has some insight in carving, the background might be
lowered and the plant modeled, the whole being finished in linseed
oil. If carving is contemplated, hard woods such as cherry or
mahogany should be used.



** Protecting the Fingers from Chemicals [283]

The finger nails and fingers may be easily protected from stains
of chemicals by coating them with a wax made up as follows: Melt
white wax in the same manner as melting glue. This may be done by
cutting the wax into small pieces, placing them in a vessel and
setting the vessel in boiling water. To each ounce of melted wax
thoroughly stir in 1 dr. of pure olive oil. The fingers should be
dipped into the wax while it is in a liquid state. This will form
a coating that will permit the free use of the fingers, yet
protects the skin from the chemicals. It is useful for
photographers.



** Combined Turning Rings and Swings [283]

This trapeze, with rings for the large boys and a swing for the
smaller ones, can be made on the same standards. Instead of the
usual two short ropes, tied and bolted through the top crosstimber
bore two holes large enough for the ropes to pass through easily.
Pass the rope along the crosspiece and down the post and tie it to
cleats nailed at a height that can be easily reached.

At the ends of the crosspiece drive two nails, allowing them to
project 1 or 2 in. This will keep the rope from slipping off when
the rings and swing are raised and lowered. All sharp edges should
be sandpapered to prevent

[Illustration: Rings and Swing]

the rope from being cut. A board with notches cut in the ends will
make a good swing board which can be removed instantly.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Homemade Telegraph Key [283]

[Illustration: Key and Connections]

A piece of wood, 1/2 in. thick, 2 in. wide and 5 in. long, is used
for the base of this instrument. Two wire nails, each 1 in. long,
are used for the cores of the magnets. Each nail is wound with
three or four layers of fine insulated magnet wire, about No. 25
gauge, similar to that used in electric bells, leaving about 1/4
in. of the end bare so that they may be driven into the wood base.
The connections for the coils are shown in the sketch, at A.

About 1 in. behind the coils is fastened a small block of wood,
the top of which is just even with the top of the nails in the
coils. A piece of tin, cut in the shape of the letter T, is
fastened with two screws to the top of this block, and the end
bent slightly so as to clear the top of the nails about 1/32 in.

The key lever is cut from a thin piece of wood, in the shape shown
in the sketch, and pivoted in a slotted block which is used as a
base for the key. A piece of bare copper wire is fastened along
the under side of the key, as shown by the dotted lines. A rubber
band, passing over the end of the key and attached to the base
with a tack, acts as a spring to keep the key open. A small piece
of tin is fastened to the base under the knob of the key. This is
for making the contact between the copper on the key and the wires
from the coils, when the key is pushed down.
--Contributed by W. H. Lynas.



** Protecting Sleeves [283]

Bicycle trousers-guards make excellent sleeve bands when the cuffs
are turned back and rolled above the elbows.



** Imitation Arms and Armor-Part VII [284]

The helmets, breastplates and gauntlets described in parts V and
VI can be used in making up a complete model

[Illustration: Full Suit of Armor]

for a full suit of armor of any size, as shown in Fig. 1. All of
the parts for the armor have been described, except that for the
legs. Figure 2 shows how the armor is modeled on the side of the
left leg. The clay is modeled as described in previous chapters,
the paper covering put on, and the tinfoil applied in imitation of
steel. The chain mail seen between and behind the tassets is made
by sewing small steel rings on a piece of cloth as shown in Fig.
3. These rings may be purchased at a hardware store or harness
shop.

The whole figure when completed is placed on a square box covered
with red or green baize. The armor should be supported by a light
frame of wood built up on the inside, says the English Mechanic,
London. Two vertical pieces are firmly attached to the box so they
will extend up inside the legs, and at the top of them is attached
a crosspiece on which is placed a vertical stick high enough to
carry the helmet. The two lower pieces must be built up and padded
out with straw, then covered with red cloth or baize to represent
the legs.

In making up the various pieces for a full model it will be found
very convenient to use rope, a stout cord or strings in making up
the patterns on the parts. Instead of using brass-headed nails,
brass paper fasteners will be found useful. These can be purchased
at a stationery store. Secure the kind having a round brass head
from which hang two brass tongues. These are pushed through a hole
and spread out flat on the opposite side. Other materials can be
used in the place of tinfoil to represent steel. Silver paper will
do very well, but if either the tinfoil or silver paper are found
difficult to manipulate, go over the armor with a coat of silver
paint put on with a brush. When dry give the surface a coat of
varnish.



** A Home-Made Tripod Holder [284]

An inexpensive tripod holder, one that will prevent the tripod
from slipping on a smooth floor, and prevent the points from doing
damage to the polished surface or puncturing an expensive rug or
carpet, can be made in a few minutes' time, says Camera Craft.

Secure two strips of wood, or ordinary plaster laths will do, and
plane them down to a thickness of 3/16 in., for the sake of
lightness. Cut them to a length or 40 in. and round off the ends
to improve their appearance. Take the piece shown in Fig. 1 and
drill a 1/4-in. hole in the center, and eight small holes, 1 in.
apart, at each end. In one end of the piece, Fig. 2, make the same
series of eight small holes and, in the other end, drill six
1/4-in. holes, 3 in. apart. A 1/4-in. flat headed carriage bolt,
about 1 in. long, completes the equipment.

The two pieces are bolted together, not too tight, and the points
of the tripod legs inserted in their respective small holes. So
set up, there is absolutely no danger of one of the legs slipping
out of position. By moving the position of the bolt from, one to
another of the larger holes in the strip, Fig. 2, almost any
desired inclination of the camera can be secured.

The same sort of simple apparatus built slightly stronger, and
with a small caster under each of the three series of small holes,
makes an

[Illustration: The Tripod Cannot Slip]

excellent tripod clamp for use when the camera has to be shifted
about, as in portraiture and the like.



** How to Weave a Shoestring Watch Fob [285]

Having procured a pair of ordinary shoestrings, take both ends of
one of them and force the ends through the middle of the other,
leaving a loop 1-1/2 in. long, as shown in Fig. 2. In this sketch,
A is the first string and B is the second, doubled and run through
the web of A. Take hold of the loop and turn it as shown in Fig.
2, allowing the four ends to hang in four directions. Start with
one end, the one marked A, in Fig. 1, for instance, and lay it
over the one to the right. Then take B and lay it over A, and the
one beneath C; lay Cover B and the one under D, and then lay D
over C and stick the end under A. Then draw all four ends up
snugly. Commence the next layer by laying the end A back over B
and D; D over A and C; C over D and B, then B over C and the end
stuck under A. Proceed in the same manner and keep on until about
1-1/2 in. of the ends remain unwoven. Four pins stuck through each
corner and into the layers will hold the ends from coming apart.
The ends of the strings are raveled out so as to make a tassel.
This will make a square fob which will appear as shown in Fig. 4.

A round fob is made in a similar way, taking the same start as for
the square fob, but instead of reversing

[Illustration: Fobs Made from Shoestrings]

the ends of each alternate layer, always lap one string, as at A
in Fig. 3. over the one to its right, as B, slipping the last end
of the four strings under and tightening all, as in making the
square fob. Fasten the ends with pins and ravel out for a tassel.
The round fob is shown in Fig. 5.

A fob in the shape of a horseshoe can be made by taking four
shoestrings and tying a small string around the middle of them,
then weaving the layers both ways from the point where the strings
are tied. A loop, 1-1/2 in. long, is left out at the center before
starting on one side. The loop is for attaching the fob to the
watch. After the weaving is complete and the tassel ends made, a
small stiff wire is forced through the center to form the shape of
a horseshoe.

Other designs can be made in the same manner. Strings of different
colors will make up a very pretty fob, especially if silk strings
are used.
--Contributed by John P. Rupp, Monroeville, Ohio.



** How to Make a Table Mat of Leather [286]

The table mat, the design of which is shown herewith, is to be
made of leather. It may be made of Russian calf and the background
modeled down

[Illustration: Pattern for the Table Mat]

as has been described in several previous articles dealing with
leather work. To do this the leather is moistened on the back side
just enough to make the leather take the impression of the tool,
but not enough to make the moisture show through on the face. Any
smooth piece of steel, such as a nut pick, that will not cut or
scratch the leather and will make a V-shaped depression will do.

A second method is to secure a piece of sheepskin and, using the
reverse side, outline the design by means of a pyrographer's
outfit. This manner of treating leather is so common that it needs
no description.

A third method is to secure a piece of sheep or goat skin, trace
the design on the reverse side by means of carbon paper, and put
the outline and design in with brush and stains such as are sold
for this purpose.

The accompanying pattern shows but one-fourth of the mat. Draw the
one-fourth on paper to the size desired and then fold on lines A
and B, tracing this one-fourth on the other parts by the insertion
of double-surfaced carbon paper.

On the calfskin the pattern is to be held on the leather and the
tool worked over the pattern to get the outline transferred. After
this the pattern is to be removed and the leather modeled.



** Sad Iron Polisher [286]

A small amount of wax is necessary on an iron for successful work.
The wax is usually applied by hand to the heated surface of the
iron. A much better and handier way is to bore five or six holes
in one end of the ironing board to a depth of half

[Illustration: Polisher]

its thickness, filling them with wax, beeswax or paraffin, and
covering them over with two thicknesses of muslin.

The rubbing of the hot iron over this cloth absorbs just enough of
the wax to make the iron work smoothly. When the supply of wax is
exhausted, it can be easily renewed.
--Contributed by A. A. Houghton, Northville, Mich.



** Making Coins Stick to Wood by Vacuum [287]

Take a quarter and place it flat against a vertical surface of
wood such

[Illustration: Floating Coin]

as the side of a bookcase, door facing or door panel, and strike
it hard with a downward sliding motion, pressing it against the
wood. Take the hand away and the coin will remain on the woodwork.
The striking and pressure expel the air between the quarter and
the wood, thus forming a vacuum sufficient to hold the coin.



** Simple and Safe Method for Sending Coins by Mail [287]

Sending coins by mail is not as a rule advisable, but sometimes it

[Illustration: How the Paper is Folded]

becomes necessary, and usually a regular coin mailer is not
available. A very simple and secure way to wrap a coin or coins
for mailing is as follows: Procure a piece of heavy paper, nearly
as wide as the envelope is long, and about 12 in. long. Fold on
the dotted lines shown by A and B in the sketch, and slip the coin
in the pocket thus formed. Fold together on lines C, D, E and F,
making the last two folds wide enough to fit snugly in the
envelope. This method holds the coin in the center of the envelope
where it cannot work around and cut through the edges.
--Contributed by O. J. Thompson, Petersburg, Ill.



** Mounting Photographs in Plaster Plaques [287]

Purchase a few pounds of plaster of paris from your local druggist
and select a dish of the desired shape in which to make your cast.
The size of the dish will depend on the size of the print to be
mounted. Select the print you wish to mount, those on matte paper
will work best, and after wetting, place it face down in the dish,
press into place and remove all drops of water with a soft cloth.
Be sure and have the print in the center of the dish. Earthen
dishes will be found more convenient, although tin ones can be
used with good success, says Photographic Times.

Mix same of the plaster in clear water so it will be a little
thick. Enough plaster should. be mixed to cover the bottom of the
dish about 1/2 in. thick. Pour the plaster into the dish over the
print and allow to stand until it becomes quite hard. The cast can
then be removed and the print should be fast to it. If the print
or plaster is inclined to stick, take a knife and gently pry
around the edges and it can be removed without breaking.

Prints of any size may be used by having the mold or dish large
enough to leave a good margin. This is a very important point as
it is the margin that adds richness to all prints. Platinum or
blueprint papers work well, but any kind that will not stick may
be used. After the plaster has thoroughly dried, any tint may be
worked on the margin by the use of water colors; if blueprints are
used, it is best to leave a plain white margin.



** Iron Rest for an Ironing Board [288]

A flatiron rest can be made on an ironing-board by driving a
number of large tacks into one end of the board. The tacks should
be about 1 in. apart and driven in only part way, leaving about
1/4 in. remaining above the surface of the board. The hot iron
will not burn the wood and it cannot slip off the tacks. This iron
rest is always with the board and ready when wanted. --Contributed
by Beatrice Oliver, New York, N. Y.

[Illustration: Iron Rest]



** Instantaneous Crystallization [288]

Dissolve 150 parts of hyposulphite of soda in 15 parts of water
and pour the solution slowly into a test tube which has been
warmed in boiling water, filling the same about onehalf full.
Dissolve in another glass 100 parts of acetate of soda in 15 parts
of boiling water. Pour this solution slowly on top of the first in
such a way that it forms an upper layer, without mixing the
solutions. The two solutions are then covered over with a thin
layer of boiling water and allowed to cool.

[Illustration: Crystallization]

Lower into the test tube a wire, at the extremity of which is
fixed a small crystal of hyposulphite of soda. The crystal
traverses the solution of acetate without causing trouble, but
crystallization will immediately set in as soon as it touches the
lower hyposulphite of soda solution, as shown at the left in the
sketch.

When the hyposulphite of soda solution becomes crystallized, lower
in the upper solution a crystal of acetate of soda suspended by
another wire, as shown in the right of the sketch, and this will
crystallize the same as the other solution.



** Decoloration of Flowers by Fumes of Sulphur [288]

Dissolve some sulphur in a small dish which will inflame by
contact with air thus forming sulphuric acid fumes. Cover the dish
with a conical chimney made of tin and expose to the upper opening
the flowers that are to be decolored. The action is very rapid and
in a short time myrtle, violets, bell flowers, roses, etc., will
be rendered perfectly white.

[Illustration: Flowers]



** How to Preserve Egg Shells [288]

Many naturalists experience difficulty in preserving valuable egg
shells. One of the most effective ways of preserving them is as
follows: After the egg is blown, melt common beeswax and force it
into the shell with a discarded fountain pen filler. Set in a cool
place until the wax hardens. The most delicate shells treated in
this manner can be handled without fear of breaking, and the
transparency of the wax will not alter the color, shading, or
delicate tints of the egg.
--Contributed by L. L. Shabino, Millstown, South Dakota.



** Homemade Phonograph [289]

Make a box large enough to hold four dry cells and use it as a
base to mount the motor on and to support the revolving cylinder.
Anyone of the various battery motors may be used to supply the
power. The support for the cylinder is first made and located on
the cover of the box in such a position that it will give ample
room for the motor. The motor base and the support are fastened by
screws turned up through the cover or top of the box. The location
of these parts is shown in Fig. 1.

The core for holding the cylindrical wax records is 4-1/2 in. long
and made of wood, turned a little tapering, the diameter at the
small or outer end being 1-5/8 in., and at the larger end, 1-7/8
in. A wood wheel with a V-shaped groove on its edge is nailed to
the larger end of the cylinder. The hole in the core is fitted
with a brass tube, driven in tightly to serve as a bearing. A rod
that will fit the brass tube, not too tightly, but which will not
wobble loose, is threaded and turned into the upper end of the
support. The core with its attached driving wheel is shown in Fig.
3. The dotted lines show the brass bearing and rod axle. The end
of the axle should be provided with a thread over which a washer
and nut are placed, to keep the core from coming off in turning.

The sound box, Fig. 2, is about 2-1/2 in. in diameter and 1 in.
thick, made of heavy tin. The diaphragm, which should be of thin
ferrotype tin, should be soldered to the box. The needle is made
of a piece of sewing needle, about 1/8s in. long, and soldered to
the center of the diaphragm. The first point should be ground
blunt, as shown in the sketch. When soldering these parts
together, take care to have the diaphragm lie perfectly flat and
not made warping by any pressure applied while the solder is
cooling.

The tin horn can be easily made, attached to the sound box with a
piece of rubber hose and held so it will swing the length of the
record by a rod attached to the top of the box, as shown.

The motor can be controlled by a small three or four-point battery
rheostat.

[Illustration: Phonograph and Construction of Parts]

--Contributed by Herbert Hahn, Chicago, Ill.



** A Substitute for a Compass [289]

An easy way to make a pencil compass when one is not at hand, is
to take a knife with two blades at one end, open one to the full
extent and the other only halfway. Stick the point end of the
fully open blade into the side of a lead pencil and use the
half-open blade as the center leg of the compass. Turn with the
knife handle to make the circle.
--Contributed by E. E. Gold. Jr. Victor, Colo.

[Illustration: Pencil on the Knife Blade]



** A Novel Rat Trap [290]

[Illustration: Rat Trap]

A boy, while playing in the yard close to a grain house, dug a
hole and buried an old-fashioned fruit jug or jar that his mother
had thrown away, says the Iowa Homestead. The top part of the jug
was left uncovered as shown in the sketch, and a hole was b r 0
ken in it just above the ground. The boy then placed some shelled
corn in the bottom, put a board on top, and weighted it with a
heavy stone.

The jug had been forgotten for several days when a farmer found
it, and, wondering what it was, he raised the board and found nine
full-grown rats and four, mice in the bottom. The trap has been in
use for some time and is opened every day or two and never fails
to have from one to six rats or mice in it.



** A Nut-Cracking Block [290]

[Illustration: Holes in the Block for Nuts]

In the sketch herewith is shown an appliance for cracking nuts
which will prevent many a bruised thumb. To anyone who has ever
tried to crack butternuts it needs no further recommendation. The
device is nothing more than a good block of hardwood with a few
holes bored in it to fit the different sized nuts. There is no
need of holding the nut with the fingers, and as hard a blow may
be struck as desired. Make the depth of the hole two-thirds the
height of the nut and the broken pieces will not scatter.
--Contributed by Albert O'Brien, Buffalo, N. Y.



** A Jelly-Making Stand [290]

Every housewife who makes jelly is only too well acquainted with
the inconvenience and danger of upsets when using the old method
of balancing a

[Illustration: Cheesecloth Strainer on Stand]

jelly-bag on a couple of chairs stood on the kitchen table, with
the additional inconvenience of having a couple of chairs on the
kitchen table out of commission for such a length of time.

The accompanying sketch shows how a stand can be made from a few
pieces of boards that will help jelly makers and prevent the
old-time dangers and disadvantages. The stand can be stood in the
corner of the kitchen, or under the kitchen table where it will be
out of danger of being upset.
--Contributed by Lyndwode, Pereira, Ottawa, Can.



** How to Make an Egg-Beater [291]

There is no reason why any cook or housewife should be without
this eggbeater, as it can be made quickly in any size. All that is
needed is an ordinary can with a tight-fitting cover-a
baking-powder can will do. Cut a round piece of wood 3 in. longer
than the length of the can. Cut a neat hole in the cover of the
can to allow the stick to pass through, and at one end of the
stick fasten, by means of a flatheaded tack, a piece of tin, cut
round, through which several holes have been punched. Secure
another piece of heavier tin of the same size, and make

[Illustration: Made Like a Churn]

a hole in the center to pass the stick through. Put a small nail 2
in. above the end of the dasher, which allows the second tin to
pass up and down in the opposite direction to the dasher. This
beater will do the work in less time than the regular kitchen
utensil.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Cart Without an Axle [291]

The boy who has a couple of cart wheels is not always lucky enough
to have an axle of the proper length to fit the wheels. In such a
case the cart can be constructed as shown in the illustration.
This cart has no axle, each wheel being attached with a short pin
for an axle, on the side and at the lower edge of the box. The
outer end of the pin is carried on a piece of wood extending the
full length of the box and

[Illustration: Wheels Fastened to the Box]

supported by crosspieces nailed to the ends, as shown.
--Contributed by Thos. De Loof, Grand Rapids, Mich.



** An Illuminated Target [291]

My youthful nephews some time ago were presented with an air rifle
and it worked so well that it became necessary for me to construct
a target that would allow the fun to be carried on at night.

I reversed a door gong, screwed it on the inside of a store box,
and fitted two candles on the inside to illuminate the bullseye.
The candles, of course, were below the level of the bullseye. The
position of the candles and gong are shown in Fig. 1. At night the
illuminated interior of the bell could be

[Illustration: FIG. 1;   FIG. 2;  Target for Night Shooting]

plainly seen as shown in Fig. 2.
--Contributed by James M. Kane, Doylestown, Pa.



** Sawing Sheet Metal [291]

Sheet metal placed between two boards in the jaws of a vise and
clamped tightly, can be sawed easily with a hacksaw.

*8 Feed Box for Chickens [292]

The sketch shows the construction of a feed box designed to
prevent the scattering of feed and give the coward

[Illustration: Chicken Feed Box]

rooster as much chance to fatten as the game cock. The base may be
made of a 1/2-in. board, 1 ft. wide and 3 ft. long, although any
of the dimensions may be varied to suit special requirements. The
ends are semi-circular pieces with a notch, 1/4 in. deep and 3 in.
wide, cut in the center of the rounding edge. The ends are
connected together with a piece of wood set in the notches. The
strip of wood is 1/4 in. thick, 2 in. wide and as long as the box.
Notches 1/8 in. wide and 1/8 in. deep are cut on the under side of
this piece of wood, 1-1/2 in. apart. Heavy pieces of wire are bent
in the form of a semi-circle, as shown. The wires are set in the
1/8-in. notches cut on the under side of the top piece of wood.
The ends of the wires are set in holes in wood pieces joining the
bases of the end pieces. The baseboard and top are separable.
--Contributed by Maurice Baudier, New Orleans, La.



** A Book Rest [292]

A book that does not open flat is rather inconvenient to write in
when one of its sides is in the position shown in Fig. 2. A
wedge-shaped piece of

[Illustration: Book Back Holders]

metal, stone or wood, as shown in Fig. 1, will, when placed as in
Fig. 3, raise the sloping half to the level of the other pages.
Cover the block with rubber, wide rubber bands or felt, to prevent
its scratching the desk top. The block can also be used as a
paperweight.



** Window Shelf for Flower Pots [292]

On the ledge formed by the top part of the lower sash of the
window I fitted a board 7 in. wide into each side of the casing,
by cutting away the ends. I placed a small bracket at each end of
the shelf, so that it would fit solidly against the lower window
sash to support the weight of the plants.

[Illustration: Shelf in Window]

One of the brackets I nailed to the shelf and the other I held in
place with a hinge, the reason being that if both were solid, the
shelf could not be put on the window, as one end must be dropped
in place before the other. Such a shelf will hold all the plants a
person can put on it. When not in use, it can be removed without
marring the casing.
--Contributed by G. A. Wood, West Union, Ia.



** Magnet for the Work Basket [292]

Tie a ribbon or strong string to the work basket and fasten a
large magnet to the other end. Needles, scissors, etc., can be
picked up without any trouble. This device is very convenient for
invalids.
--Contributed by Nellie Conlon, Worcester, Mass.



** Knife Made from a Hack-Saw Blade [293]

A very serviceable knife with excellent cutting qualities can be
made easily from a discarded hack-saw blade. The dimensions given
in the sketch make a knife of convenient size.

The saw teeth are ground off on an emery wheel or grindstone to a
smooth edge parallel with the back edge. For the handle, take two
pieces of hard wood, dressing one surface of each piece, and cut a
groove as wide and thick as the saw blade. Place the blade in the
groove and glue the two dressed sides of the wood together. After
the glue has dried, the blade can be pulled out of the groove and
the wood shaped to any desired form. A small wood-screw is put
through one side of the handle to prevent the blade from sliding.
After completing the

[Illustration: Details of Handle]

handle, the blade is put back into the groove and sharpened to a
cutting edge.
--Contributed by H. A. Hutchins, Cleveland, Ohio.



** Killing Mice and Rats [293]

A simple and inexpensive means for killing mice and rats is to
leave yeast cakes lying around where they can eat them.
--Contributed by Maud McKee, Erie, Pa.



** Roller Coaster Illusion Traveling Up an Incline [293]

A toy car with a paddle wheel and a shaft on both ends traveling
upward on a chute in which water is flowing down, is shown in the
accompanying sketch. The paddle wheels travel in a reverse
direction causing the ends of the axles to roll on the edge of the
chute, thus carrying the car up the incline. If a rack is used on
each side of the chute and a small pinion on the

[Illustration: Car Travels Uphill]

ends of the axles, a positive upward movement of the car will be
obtained.
--Contributed by W. S. Jacobs, Malden; Mass.



** Block for Planing Octagonal Wood Pieces [293]

The little device shown in the illustration will be found very
useful in any workshop. Two or three of them will be necessary for
planing long pieces. Each one is made of a hardwood block, 1 in.
square and 4 in. long. A notch is cut in one side, as shown in
Fig. 1, so a piece of wood which has been planed square will fit
in it. Put a screw in the end of each piece and fasten it down to
the bench. If desired, a tenon may be made on the bottom of each
block, as shown in Fig. 2, to fit a mortise cut in the bench.
Place the blocks far enough apart so the board to be planed will
rest firmly in the notches.

[Illustration: The Notch Holds the Wood]

Plane the board square first and then place it in the notches and
plane the corners down to the proper dimensions.
--Contributed by Willie Woolsen, Cape May Point, N.J.



** A Letter Holder of Pierced Metal [294]

The letter holder shown in the illustration will be found
convenient for holding out-going letters that await the postman's
coming. It can be made of either copper or brass and need not

[Illustration: Finished Letter Holder]

be of very heavy material. Gauge 22 will be sufficiently heavy.
One sheet of metal, 6 by 9-1/2 in., a board on which to work it,
and an awl and hammer, will be needed. Prepare a design for the
front. If one such as is shown is to be used,

[Illustration: Layout for the Metal]

make one-quarter of it first, and then get the other parts by
folding on the center lines and tracing. This will insure having
all parts alike. The letters can be put on afterward.

Fasten the metal to the board, using tacks and nailing outside of
the required space, in the waste metal. Trace the design on the
metal with carbon paper; or, if desired, paste the paper design
right on the metal. With an awl pierce the metal between the
marginal line and the design, as shown. The holes should be
uniform along the outlines but should be pierced promiscuously
otherwise. On the back, only the marginal line is to be pierced.

Remove the metal, together with the paper if the latter was pasted
to the metal, and trim off the surplus metal where the tacks had
been placed. File off any sharpness so that the hand may not be
injured in handling it. Place the metal on the edge of a table or
between two boards, and bend on the two lines indicated in the
drawing, to right angles.

A good finish is obtained by just letting the copper age with its
natural color. If any polishing is required, it should be done
before the metal is fastened to the board and pierced.



** Imitating Ground Glass [294]

Make a mixture of white lead in oil, 1 part; varnish, 3/4 part;
turpentine, 1/4 part, and add sugar of lead as a dryer. Make a
very thin paint of this and use a broad, flat brush, says Master
Painter. With care you may succeed in getting the paint on quite
evenly all over, which is desirable. One coat will do. If it
becomes necessary to remove this coating for renewal, it may be
effected by an application of potash lye, or the old may be
renewed by a coating of a mixture of 2 parts hydrochloric acid, 2
parts white vitriol, 1 part sulphate of copper (blue vitriol) and
1 part of gum arabic, applied by means of a brush.



** Draw before Cutting [294]

A detail drawing made of a piece of furniture before starting the
work will often save time and mistakes.



** Making "Spirits" Play a Violin [295]

A very pretty trick, that can be worked in your own parlor, will
produce as much sensation as a fake "medium." In all appearance, a
violin, mandolin or guitar, placed on a table, will begin to
produce music simply through stamping the foot and a few passes of
the hand. The music will not sound natural, but weird and distant.

The trick is done by placing the end of a small stick on a music
box in the basement of the house and allowing the other end to
pass up through the floor and table top so it will project about
1/16 in. The stick may be placed by the side of, behind or through
the center of a table leg. Be careful not to have any obstruction
in the way of the stick. The instrument is placed sideways on the
protruding end of the stick. The "fake" work of invoking the
"spirit" is performed and ended by stamping the foot, which
signals the operator in the basement to start the machine, and the
violin seemingly produces music without anyone touching it.

So impressive are the results, that many people really think the
spirits of the departed are playing the violin with unseen hands.
The music is transmitted through the stick from the music box to
the violin.

[Illustration: The Music Produced by the Phonograph is Transmitted
to the Viohn on the Second Floor by the Aid of a Long Stick]



** Sizing a Threaded Hole [295]

It sometimes becomes necessary to transfer the size of a threaded
hole from some out-of-the-way place to the shop in order to make a
piece to fit it. With proper tools this is easy; without them, it
might be difficult. One thing is always at hand and that is wood.
Whittle a stick tapering until it starts in the hole. Then turn it
into the hole and a fair thread will be made on the wood. The
stick can be carried in the pocket without risk of changing the
size, as would be the case with ordinary calipers.



** Leaded-Glass Fire Screen [295]

The main frame of the fire screen shown in Fig. 1 is made from two
pieces of 1/2-in. square bar iron. The longest piece, which should
be about 5-1/2 ft. long, is bent square so as to form two
uprights, each 28 in. long and measuring 26 in. across the top.
The bottom crosspiece can be either riveted or welded to the
uprights. Two pairs of feet, each 6 in. long and spread about 8
in. apart, are shaped as shown in Fig. 2. These are welded to the
lower end of the uprights.

The ornamental scrollwork on the frame is simple and effective,
and is easy to construct, says Work, London. The scrolls are
attached to the frame by means of 3/16-in. round-head machine
screws. The leaf ornament at the

[Illustration: Completed Fire Screen and Parts]

termination of the scroll is shaped and embossed as shown in Fig.
3. The metal used for the scrolls is 3/16 in. thick by 1/2 in.
wide. The leaf ornament is formed by turning over the end of a
piece of metal and working it together at a welding heat, and then
shaping out the leaf with' a chisel and files, after which they
are embossed with a ballpeen hammer.

The center is made from colored glass of special make for leaded
work. The design is formed in the lead, of which a cross section
is shown in Fig. 4. Use care to give the lead a symmetrical
outline. The design should be drawn full size on a large sheet of
heavy paper and the spaces to be occupied by the lead cut out so
as to leave the exact size and shape of each piece of paper the
same as wanted for each piece of glass. These are used as patterns
in marking the glass for cutting. The glass is cut the same as
ordinary window glass. The glass, lead, border and special flux
can be purchased from an art glass shop.

After the glass is cut, the work of putting the pieces together
with the lead between them is begun. Secure a board as wide as the
screen--several narrow boards put together will do and begin by
placing one vertical side border, A, Fig. 5, and the base border,
B, on it as shown. Place the corner piece of glass, C, in the
grooves of the borders, cut a long piece of lead, D, and hold it
in place with two or three brads or glazier's points. The piece of
lead E is cut and a small tenon joint made as shown in Fig. 6.
While the piece of lead D, Fig. 5, is held by the brads, the piece
E can be fitted and soldered. The soldering is done with a hot
soldering iron and wire solder, using rosin as a flux, or, better
still, special flux purchased for this purpose. After the joints
are soldered, the piece of glass F is put in place and the lead
held with brads as before until the cross leads are fitted and
soldered. The brads are then removed, the glass piece as shown by
the dotted lines put in, and the leads around it held with brads
until the crosspieces are put in and soldered. This method is
pursued until the glass is complete, then the two remaining
vertical and top pieces of border are put on and all corners
soldered.

The leaded glass is held in the iron frame by means of eight
U-shaped clips, as shown in Fig. 7. A hole is drilled in the frame
for the retaining screw, the latter being tapped to the base of
the clip. Special screws may be made with ornamental heads, as
shown in Fig. 8, and used for securing the side scrolls and clips
together.



** A Revolving Teeter Board [297]

[Illustration: Details of Teeter Board ]

The accompanying sketch shows the details of a revolving teeter
board for the children's playground that can be constructed in a
few hours. Secure a post, not less than 4 in. square and of the
length given in the drawing, and round the corners of one end for
a ring. This ring can be made of 1-in. strap iron and it should be
shrunk on the post. Bore a 3/4-in. hole in the end of the post for
the center pin to rest in. Make three washers 3-in. in diameter
and 1/4 in. thick and drill 3/4-in. holes through their centers.
Drill and countersink two smaller holes for 2-in. wood screws in
each washer. Fasten one of these washers to the top of the post as
shown. The post is now ready to be set in the ground. Coarse
gravel should be packed tightly about it to make it solid.
Concrete is much better if it can be secured.

To make the swivel you will need two 1/4 by 5 by 8-in. plates,
rounded at the top as shown, and two wood blocks, A and B, each
3-1/2 by 5 by 10 in. Drill the lower ends of the plates for four
2-1/2-in. lag screws and the upper ends for a 5/8-in. bolt. Fasten
the plates to the block B, then drill a 3/4-in. hole as shown and
fasten the two remaining washers to the block, one on each side
and central with the hole. Bore a 5/8-in. hole lengthwise through
the block A for the 5/8-in. rocker bolt. This bolt should be
11-1/2 in. long.

The teeter board is made of a 2 by 12-in. plank about 12 ft. long.
It should be slightly tapered from the center to the ends. Two
styles of hand holds are shown, but the one on the left is the one
most generally used. The handles are rounded at the ends and are
fastened to the board with lag screws or bolts. The block A is
fastened to the board with lag screws and should be a working fit
between the wo plates where it is held by means of the 5/8-in.
bolt. The center pin is 3/4-in. in diameter and about 9 in. long.
--Contributed by W. H. Dreier, Jr., Camden, N. J.



** Home-Made Pot Covers [297]

Empty thread spools and the tins used as extra inside covers in
lard cans are usually thrown away, but these can be put to good
use as kettle covers, if they are made up as follows: Saw the
spool in half as shown, make a hole in the center of the tin and
run a screw or nail through the spool and the tin; then flatten
its end on the under side. This will make an excellent cover for a
pot.
--Contributed by Maurice Baudier, New Orleans, La.

[Illustration: Pot Covers]



** An Outdoor Gymnasium Part I-The Horizontal Bar [298]

Gymnastic apparatus costs money and needs to be housed, because it
will not stand the weather. Gymnasiums are not always available
for the average boy who likes exercise and who would like to learn
the tricks on horizontal and parallel bars, horse and rings, which
all young athletes are taught in regular gymnastic courses.

Any small crowd of boys--even two--having a few simple tools, a
will to use them and the small amount of money required to buy the
necessary

[Illustration: Adjustable Horizontal Bar

wood, bolts and rope, can make a first class gymnasium. If trees
are convenient, and some one can swing an axe, the money outlay
will be almost nothing. The following plans are for material
purchased from a mill squared and cut to length. To substitute
small, straight trees for the squared timbers requires but little
changes in the plans.

The most important piece of apparatus in the gymnasium is the
horizontal bar. Most gymnasiums have two: one adjustable bar for
various exercises and a high bar for gymnastic work. The outdoor
gymnasium combines the two. The material required is as follows: 2
pieces of wood, 4 in. square by 9-1/2 ft. long; 4 pieces, 2 by 4
in. by 2 ft. long; 4 pieces, 1 by 7 in. by 6-1/2 ft. long; 4
filler pieces, 3/4 by 3 in. by 3 ft. 9 in. long and 1 piece, 2-1/2
in. square by 5 ft. 7 in. long. This latter piece is for the bar
and should be of well seasoned, straight-grained hickory. It makes
no difference what kind of wood is used for the other pieces, but
it is best to use cedar for the heavy pieces that are set in the
ground as it will take years for this wood to rot. Ordinary yellow
pine will do very well. The four 7-in. boards should be of some
hard wood if possible such as oak, hickory, maple, chestnut or
ash. The other material necessary consists of 2 bolts, 1/2 in. in
diameter and 7 in. long; 16 screws, 3 in. long; 4 heavy screw eyes
with two 1/2-in. shanks; 50 ft. of heavy galvanized wire: 80 ft.
of 1/4-in. manila rope and 4 pulley blocks. Four cleats are also
required but these can be made of wood at home.

Draw a line on the four 7-in. boards along the side of each from
end to end, 1-1/4-in. from one edge. Beginning at one end of each
board make pencil dots on this line 5 in. apart for a distance of
3 ft. 4 in. Bore holes through the boards on these marks with a
9/15-in. bit. Fasten two of these boards on each post with the
3-in. screws, as shown in the top view of the post Fig. 1, forming
a channel of the edges in which the holes were bored. Two of the
filler pieces are fastened in each channel as shown, so as to make
the space fit the squared end of the bar snugly. The ends of the
boards with the holes should be flush with the top of the post.
This will make each pair of holes in the 7-in. boards coincide, so
the 1/2-in. bolt can be put through them and the squared end of
the bar.

Select a level place where the apparatus is to be placed and dig
two holes 6 ft. apart, each 3 ft. deep and remove all loose dirt.
The ends of the posts not covered with the boards are set in these
holes on bricks or small stones. The channels formed by the boards
must be set facing each other with the inner surfaces of the posts
parallel and 5 ft. 8 in. apart. The holes around the posts are
filled with earth and well tamped.

The hickory piece which is to form the bar should be planed,
scraped and sandpapered until it is perfectly smooth and round
except for 3 in. at each end. Bore a 9/16-in. hole through each
square end 1-1/4 in. from the end. The bar may be fastened at any
desired height by slipping the 1/2-in. bolts through the holes
bored in both the bar and channel.

Each post must be well braced to keep it rigid while a person is
swinging on the bar. Four anchors are placed in the ground at the
corners of an imaginary rectangle 9 by 16 ft., in the center of
which the posts stand as shown in Fig. 2. Each anchor is made of
one 2-ft. piece of wood, around the center of which four strands
of the heavy galvanized wire are twisted, then buried to a depth
of 2 ft., the extending ends of the wires coming up to the surface
at an angle.

The heavy screw eyes are turned into the posts at the top and
lengths of ropes tied to each. These ropes or guys pass through
the pulley blocks, which are fastened to the projecting ends of
the anchor wire, and return to the posts where they are tied to
cleats. Do not tighten the guy ropes without the bar in place, as
to do so will strain the posts in the ground. Do not change the
elevation of the bar without slacking up on the ropes. It takes
but little pull on the guy ropes to make them taut, and once
tightened the bar will be rigid.

[Illustration: Ground Plan]

Oil the bar when it is finished and remove it during the winter.
It is well to oil the wood occasionally during the summer and
reverse the bar at times to prevent its becoming curved. The wood
parts should be well painted to protect them from the weather.



** Electrostatic Illumination [299]

Anyone having the use of a static machine can perform the
following experiment which gives a striking result. A common
tumbler is mounted on a revolving

[Illustration: Illuminated Tumbler]

platform and a narrow strip of tinfoil is fastened with shellac
varnish to the surface of the glass as follows: Starting beneath
the foot of the glass from a point immediately below the stem, it
is taken to the edge of the foot; it follows the edge for about 1
in. and then passes in a curve across the base, and ascends the
stem; then it passes around the bowl in a sinuous course to the
rim, which it follows for about one-third of its circumference;
after which it descends on the inside and terminates at the
bottom. The tinfoil on the outside of the glass is divided by
cutting with a knife every 1/8 in., the parts inside and beneath
the glass being left undivided. Current is then led from a static
machine to two terminals, one terminal being connected to one end
of the tinfoil strip, and similarly the second terminal makes
contact with the other end. As soon as the current is led into the
apparatus, a spark is seen at each place where the knife has cut
through the tinfoil. If the tumbler is rotated, the effect will be
as shown in the illustration. A variety of small and peculiar
effects can be obtained by making some of the gaps in the tinfoil
larger than others, in which case larger sparks would be produced
at these points. The experiment should be carried out in a
darkened room, and under these circumstances when nothing is
visible, not even the tumbler, the effect is very striking.



** Balloon Ascension Illusion [300]
By C. W. Nieman

In these days of startling revelations in air-craft flight we are
prepared to see any day some marvelous machine driven bird cutting
figure-eights all over the sky above our heads. One boy recently
took advantage of this state of expectancy to have an evening's
harmless amusement, through an illusion which deceived even the
most incredulous. He caused a whole hotel-full of people to gaze
open mouthed at a sort of "Zeppelin XXIII," which skimmed along
the distant horizon, just visible against the dark evening sky,
disappearing only to reappear again, and working the whole crowd
up to a frenzy of excitement. And all he used was a black thread,
a big piece of cardboard and a pair of field glasses.

He stretched the thread between two buildings, about 100 ft.
apart, in an endless belt, passing through a screweye at either
end. On this thread he fastened a cardboard "cut-out" of a
dirigible, not much to look at in daytime, but most deceptive at
dusk. By pulling one or the other string he moved the "airship" in
either direction. He took the precaution of stretching his thread
just beyond a blackberry hedge and thus kept over-inquisitive
persons at a safe distance. He also saw to it that there was a
black background at either end so that the reversing of the
direction of the craft would not be noticed.

In attracting the crowd he had a confederate stand looking at the
moving ship through a field glass, which at once gave the
suggestion of distance, and materially heightened the illusion.
When the interest of the crowd, which at once gathered, was at its
height, the "aeronaut" pulled his craft out of sight and let the
disillusion come when the light of day laid bare his fraud.



** A Cork Extractor [300]

The device shown in the sketch is for removing a cork or stopper
from a bottle whether full or empty where the cork has been pushed
inside. A wire about No. 14 gauge is bent as shown at B, Fig. 1,
to fit the index finger and the other end filed to a point C, and
turned in a spiral D, so the point will be on top. Insert this
tool in the bottle as shown in Fig. 2 and place the end D under
the cork and pull up. The cork will come out easily. --Contributed
by Maurice Baudier. New Orleans. La.

[Illustration: Cork Extractor]



** An Outdoor Gymnasium Part II-Parallel Bars [301]

Parallel bars hold a high place in the affection of those who
frequent gymnasiums as the best apparatus for development of the
back and shoulder muscles, as well as a promoter of ease and grace
of movement. The outdoor "gym" can have a set of these bars with
very little more labor than was required for the horizontal bar.

The material required is as follows:

[Illustration: Detail of the Parallel Bars]

4 posts, preferably cedar, 4 in. square and 6 ft. long;
2 base pieces, 4 in. square and 5-1/2 ft. long;
2 cross braces, 2 by 4 in. by 2 ft. 2 in. long;
2 side braces, 2 by 4 in. by 7 ft. 8 in. long;
4 knee braces, 2 by 4 in. by 3 ft. 8 in. long;
2 bars of straight grained hickory, 2 by 3 in. by 10 ft. long;
4 wood screws, 6 in. long;
4 bolts, 8 in. long; 8 bolts, 7 in. long and
1 doz. large spikes.

To make the apparatus, lay off the bases as shown in the end view
and bevel the ends at an angle of 60 deg. Chisel out two notches 4
in. wide and 1 in. deep, beginning at a point 9 in. from either
side of the center. These are to receive the lower ends of the
posts. Bevel two sides of one end of each post down to the width
of the finished bar--a little less than 2 in. Cut notches in these
ends to receive the oval bars. Bevel the ends of the knee braces,
as shown in the diagram, and fasten the lower ends to the beveled
ends of the bases with the spikes. Fasten the upper ends of the
knee braces to the uprights with the 8-in. bolts put through the
holes bored for that purpose, and countersinking the heads. Lay
the whole end flat on the ground and make a mark 2-1/2 ft. from
the bottom of the base up along the posts, and fasten the end
braces with their top edges flush with the marks, using four of
the 7-in bolts. Finally toe-nail the base into the ends of the
posts merely to hold them in position while the whole structure is
being handled.

Two endpieces must be made. These sets or ends of the apparatus
are to be buried in trenches dug to the depth of 2-1/2 ft., with
the distance between the two inner surfaces of the posts, which
face each other, of 7 ft. After the trenches are dug, additional
long, shallow trenches must be made connecting the posts to
receive the side braces. The function of these side braces is to
hold both ends together solidly. It is necessary to bury these
braces so they will be out of the way of the performer. The side
braces are bolted to the posts just below the cross braces, so the
bolts in both will not meet. The bars are dressed down so that a
cross section is oval as shown in the end view. They are to be
screwed to the notched ends of the uprights with the 6-in. screws.
The holes should be countersunk so they can be filled with putty
after the screws are in place. The bars should be well oiled with
linseed oil to protect them from the weather, and in the winter
they should be removed and stored.

Every piece of wood in this apparatus can be round and cut from
trees, except the bars. If using mill-cut lumber, leave it
undressed, and if using round timber leave the bark upon it as a
protection from the weather. It is well to paint the entire
apparatus, save the bars, before burying the lower part of the end
pieces. The wood so treated will last for years, but even
unpainted they are very durable. Be sure to tamp down the earth
well about the posts. A smooth piece of ground should be selected
on which to erect the apparatus. (To be Continued.)



** Combined Ladle and Strainer [302]

When using a strainer in connection with a ladle the operation
requires both

[Illustration: Ladle and Strainer]

hands. A convenient article where a ladle and strainer are needed
is to swing a cup-shaped strainer under the bowl of a ladle as
shown in the illustration. The strainer can be held in place with
small bands that fit loosely over the handle and a small tip
soldered to the ladle. These will allow the ladle to be turned,
leaving the strainer always in position. A large sized ladle,
equipped with a strainer, is just the thing for painters to dip
and strain paint, while a small one is of great assistance to the
housewife for dipping and straining soups, jellies, etc.
--Contributed by W. A. Jaquythe, Richmond, Cal.



** Cleaning Gloves [302]

A solution consisting of 1 dr. of sodium carbonate and 1 qt. of
milk makes an excellent cleaner for motorists' gloves.



** Turpentine in Cutting Oil [302]

When cutting steel or wrought iron in a lathe, milling machine,
drill press or planer, it is sometimes necessary to leave a smooth
surface. Oil, or various cutting compounds of oil, is used for
this purpose and to keep the surface cool. If a little turpentine
is added to the oil, it will greatly assist in leaving a smooth
surface. A proportion of one-quarter turpentine is good.



** Center of Gravity Experiment [302]

This experiment consists of suspending a pail of water from a
stick placed upon a table as shown in the accompanying sketch. In
order to accomplish this experiment, which seems impossible, it is
necessary to place a stick, A, of sufficient length,

[Illustration: Experiment]

between the end of the stick on the table and the bottom of the
pail. This makes the center of gravity somewhere near the middle
of the stick on the table, thus holding the pail as shown.



** Lathe Accuracy [302]

A heavy lathe cut will not do accurate work.



** An Outdoor Gymnasium PART III-The Horse [303]

The German horse is that peculiar piece of apparatus which is
partly a horizontal obstruction to leap over, partly a barrier for
jumps, partly a smooth surface of long and narrow dimensions over
and about which the body may slide and swing, and partly an
artificial back for the purpose of a peculiar style of leap frog.

[Illustration: The German Horse]

To make a horse for the outdoor "gym" requires no difficult work
save the preparation of the top or body of the horse. The making
of the regular gymnasium horse requires a very elaborate
wood-working and leather upholstering plant, but the one used for
outdoor work can be made of a log of wood. Procure from a saw
mill, wood yard or from the woods, one-half of a tree trunk from a
tree 9 to 15 in. in diameter--the larger the better. The length
may be anywhere from 4 to 7 ft., but 5 ft. is a good length.

The round part of this log must be planed, scraped and sandpapered
until it is perfectly smooth, and free from knots, projections and
splinters. Hand holds must be provided next. These are placed 18
in. apart in a central position on the horse. Make two parallel
saw cuts 2 in. apart, straight down in the round surface of the
horse until each cut is 9 in. long. Chisel out the wood between
the cuts and in the mortises thus made insert the hand holds. Each
hand hold is made of a 9-in. piece of 2 by 4-in. stud cut rounding
on one edge. These are well nailed in place.

The body of the horse is to be fastened on top of posts so that it
may be adjusted for height. It is not as difficult to make as the
horizontal and parallel bars. The material required is as follows:
Two posts, 4 in. square by 5 ft. long; 2 adjusting pieces, 2 by 4
in. by 3 ft. 3 in. long; 1 cross brace, 2 by 4 in. by 3 ft. long;
2 bases, 4 in. square by 5-1/2 ft. long; 4 knee braces, 2 by 4 in.
by 3 ft. long; two 1/2-in. bolts, 1 in. long, to fasten the knee
braces at the top; ten 1/2-in. bolts, 7 in. long, 4 to fasten the
knee braces at the bottom, 2 to fasten the cross brace and 4 to be
used in fastening the adjusting pieces to the posts.

To construct, layout the bases as shown in the drawing, making the
mortises to receive the bottom ends of the posts exactly in the
center, and cut a slanting mortise 6 in. from each end to receive
the ends of the knee braces. Bevel the ends of the knee braces and
fasten the upper ends of each pair to the post with one 9-in.
bolt. Fasten the lower ends to the base with the 7-in. bolts.

The upper end of each post should have 5/8-in. holes bored through
it parallel to the base at intervals of 3 in., beginning 1-1/2 in.
from the top and extending down its length for 2 ft. 4-1/2 in. The
adjusting pieces are to be bored in a similar manner after which
they are to be mortised into the under side of the horse top 15
in. from each end, and secured with screws put through the top and
into the end of the adjusting pieces.

The bases with their posts and knee braces are buried 2 ft. 4 in.
in the ground, parallel to each other and the same distance apart
as the adjusting pieces are mortised in the horse top. When the
ground has been filled in and tamped hard, the cross brace should
be bolted in position with its lower edge resting on the ground
and connecting the two posts.

The height of the horse from the ground is adjusted by changing
the bolts in the different holes connecting the two adjusting
pieces with the two posts. Much pleasant and healthful gymnastic
exercise can be had in competitive horse jumping and leaping, the
handles providing a way to make many different leaps through, over
and around, including not only those made to see who can go over
the horse from a standing or running start at the greatest height,
but who can go over at the greatest height when starting from the
"toeing off mark" farthest away from the horse. This horse should
be located on level ground having smooth space about it for
several feet.



** Spoon Rest for Kettles [304]

A rest for keeping spoons from slipping into kettles can be made
from

[Illustration: Spoon Rest]

a strip of metal bent as shown in the illustration. The spring of
the metal will make it easy to apply to the kettle. The spoon
placed in the rest will drain back into the kettle. The cover can
be placed on without removing the spoon.
--Contributed by W. A. Jaquythe, Richmond. Cal.



** Reason for Bursting of Gun Barrels [304]

Gun barrels do not burst without a cause and usually that cause is
one of which the shooter is entirely ignorant, but nevertheless,
no one is responsible but himself, says the Sporting Goods Dealer.
Gun barrels can only burst by having some obstruction in the
barrel or by overloading with powder. Any gun barrel can be burst
by misuse or by carelessly loading smokeless powder, but no barrel
will burst by using factory loaded ammunition, provided there is
no obstruction or foreign substance inside the barrel. When a gun
barrel bursts at the breech or chamber, it is caused by an
overloaded shell, and when it bursts in the center or near the
muzzle, it is caused by some obstruction, such as a dent, snow,
water, etc.



** Hand Sled Made of Pipe and Fittings [305]

The accompanying sketch shows how an ordinary hand sled can be
made of 3/4-in. pipe and fittings. Each runner is made of one
piece of pipe bent to the proper shape. This can be accomplished
by filling the pipe with melted rosin or lead, then bending to the
shape desired, and afterward removing the rosin or lead by
heating. Each joint is turned up tightly and well pinned or
brazed. One of the top crosspieces should have right-hand and
left-hand threads or be fitted with a union. Also, one of the top
pieces connecting the rear part to the front part of each runner
must be fitted in the same way. The top is fastened to the two
crosspieces. Such a hand sled can be made in a

[Illustration: Parts Made of Pipe Fittings]

few hours' time and, when complete, is much better than a wood
sled.
--Contributed by James E. Noble, Toronto, Ontario.



** Emergency Magnifying Glass [305]

When in need of a microscope in the study of botany, one may be
made in the following manner: Bend a small wire or the stem of a
leaf so as to form a small loop not larger than the ordinary drop
of water.


Loop Inclosing a Drop of Water

When this is done place a drop of clear water in the loop and the
microscope is complete. This temporary device will prove valuable
where a strong magnifying glass is not at hand.
--Contributed by Arthur E. Joerin, Paris, France.



** Bent-Iron Pipe Rack [305]

Strips of soft iron, 1/4 or 3/16 in. in width and 1/32 in.
thick, are used in

[Illustration: Design of a Rack]

making the pipe rack shown in Fig. 1. This material can be
obtained from any local hardware dealer who carries bar iron in
stock.

Draw a full-size sketch of the design on paper, then run a string
over each part, which, when straightened out, will give the
length. The scrolls are bent with a pair of round-nose pliers.
These, with a pair of flat-nose pliers, are all the tools
necessary. The part for holding the pipes is shown in Fig. 2. The
end elevation, at E and F, shows how the rack is fastened to the
main frame of the rack.
--Contributed by J. W. Vener, Boston, Mass.



** To Clean Silver [305]

A good method to clean silver of any kind is to place the articles
in an aluminum vessel and add a few pieces of zinc. Hot water is
added and the silver boiled until clean. It is best to use soft
water. The tarnish is removed by the electrolytic action of the
zinc on the aluminum and the silver, and the latter will take on a
bright luster. This method of cleaning will not injure oxidized or
black silver, nor that which is partly oxidized.



** Sharpening Skates with a File [306

Two methods are shown in the sketches for filing skates-one for
hollow filing and the other for filing flat

[Illustration: Filing a Flat Surface]

and straight across the blade. The method shown in Figs. 1 and 2
is for filing the blade flat. The device for holding the skates
consists of a board on which four blocks, AA and BB, are nailed.
These blocks are fastened on the board in the relative positions
of the heel and sole on a shoe. The skates are clamped on them in
the same manner as on a shoe. A flat file is drawn across both
blades of the skates as shown. After the roundness is cut down on
the edges of the blades the skates are removed and the file is
drawn along the sides to remove the

[Illustration: Filing a Curved Surface]

burr. Skates filed in this way have flat surfaces with sharp
edges.

Some skaters like a hollow-ground skate and the method shown in
Figs. 3 and 4 can be used for filing a slightly curved surface in
the blade. A piece of tin or sheet metal is shaped over a round
file as shown in Fig. 3. The manner of filing the curves is shown
in Fig. 4. The piece of metal is held over the file and blade of
the skate as the file is worked.



** Lines and Letters Made with a Carpenter's Pencil [306]

The sketch shows some unusual work made with a carpenter's
pencil. If the flat lead is notched with a three-cornered file
(Fig. 1), two parallel lines may be drawn at one stroke, or
various rulings may be made, as shown in Fig. 2. Broad lines can
be made, as shown in Fig. 3, or unequal widths as in Fig. 4.

[Illustration: Pencil Points and Their Work]

In Figs. 2, 5 and 6 are shown lines especially adapted for the
bookkeeper or draftsman. If one lacks the ability to draw old
English letters with a pen, the letters may be first drawn with a
carpenter's pencil (Fig. 7) and the outlines marked with ink and
finally filled in. Narrow lines are made with points cut as in
Figs. 8 and 9. A little practice with the carpenter's pencil in
making these letters will enable the student to finally produce
them with the pen used for the purpose.



** Insulating Aluminum Wire [306]

Aluminum wire plunged hot into a cold solution of carbonate of
soda becomes coated with a strong layer of oxide which forms an
excellent insulator to electricity.



** How to Build an Ice-Yacht  [307]
Condensed from an article by H. Percy Ashley in Rudder.

The plans and specifications shown in the illustrations are for
making a 400-ft. class ice-yacht, having a double cockpit to
accommodate four persons. The weight of the persons in the forward
cockpit keeps the boat from rearing when in a stiff breeze. The
forward cockpit can be removed if necessary. The materials used
are: backbone,

[Illustration: Ice-Yacht Complete]

white pine; center, clear spruce; sides, white oak caps; runner
plank, basswood, butternut or oak; cockpit, oak; runners, chocks,
etc., quartered white oak. All the iron work should be first-grade
Swedish iron, with the exception of the runners, which are soft
cast iron.

It is not necessary to go into detail with the measurements as
they are plainly shown in the sketches. The backbone is 37-1/2 ft.
over all, 12 in. in the center, 5 in. stern, 3-1/2 in. at the
nose; width 4-1/2 in. All wood should be selected from the best
grades, well seasoned and free from checks. In Fig. 1 is shown the
complete ice-yacht with general dimensions for the sail and main
parts. Other dimensions are shown in Fig-, 2. The backbone is
capped on the upper and lower edges full length with strips of
oak, 4-1/4 in. wide and 5/8 in. thick. The lengthwise side strips
of spruce are 1-1/4 in. thick. The filling-in pieces placed
between the side pieces are of seasoned white pine, leaving the
open places as shown in Fig. 2. The parts are put together with
hot glue and brass screws.

The runner plank should be placed

[Illustration: Details of the Ice-Yacht Parts]

with the heart of the wood up, so as to give the natural curve
from the ice so that it will act as a spring. The plank is 16 in.
wide in the center, 14 in. at the ends; 4-1/8 in. thick at the
center and 2-3/4 in. at the ends.

Details of the runners are shown in Figs. 3, 4, 5, 6, 7, 8 and 9.
The cast iron shoes are filed and finished with emery paper,
making the angle on the cutting edge 45 deg. on both sides. The
runners are 7-1/4 in. wide over all and 2-1/8 in. thick. The soft
iron casting is 2-1/4 in. deep. The shoes are fastened by 5/8-in.
machine bolts. These are shown in Figs. 3 and 9. The rudder is
2-3/4 in. thick, 5 in. deep, including wood and iron, and 3 ft.
long. The cast iron shoe is 1-7/8 in. deep and fastened on with
four 1/2-in. machine bolts. A brass plate, 1/4 in. thick, 2 in.
wide and 7 in. long, is inserted on each side of the runners as
shown in Fig. 9. Three holes are drilled through for a 3/4-in.
riding bolt that can be shifted as desired for rough or smooth
ice. The runner chocks and guides are 1-7/8 in. thick and 4-1/2
in. deep. They are set in the runner plank 1/4 in. and fastened
with glue and 1/2-in. lag screws. These are shown in Figs. 6 and
7.

The aft cockpit is stationary, while the fore or passenger cockpit
can be removed at will. Both cockpits are the same size, 42 in.
wide and 7 ft. long over all. Each one has a bent rail, 1-1/2 in.
by 4 in., grooved 1/2 in. by 7/8 in. before bending. The flooring
is of oak, 1-1/2 in. thick and 4 in. wide, tongue-and grooved. The
forward cockpit is made in halves and hung on the backbone with
wrought-iron straps and bolts. These are shown in Figs. 41, 43 and
44. Two pieces of oak, 1/2 in, by 4 in. are fastened with screws
to the flooring, parallel with the backbone in the forward
cockpit. The runner plank which passes under this cockpit gives it
stability.

The spars should be hollow and have the following dimensions:
Mast, 23 ft. 3 in.; heel, 3-3/4 in. ; center, 5-1/4 in.; tip, 4
in. ; boom 23-1/2 ft.; heel, 3-3/4 in. ;center, 4 in.; tip, 2-7/8
in. at ends; gaff, 12-1/2 ft.; center, 3-1/2 in.; ends, 2-1/2 in.;
jib-boom, 10-1/2 ft.; 1-3/4 in. at the ends, 2-1/8 in. at the
center. The gaff is furnished with bent jaws of oak, Fig. 17, and
the main boom with gooseneck, Fig. 12.

Galvanized cast-steel yacht rigging, 5/16 in. in diameter, is used
for the shrouds; jibstay, 3/8 in. in diameter; runner plank guys,
5/16 in. in diameter; bobstay, 3/8 in. in diameter; martingale
stay, 1/4 in. in diameter. The throat,and peak halyards are 3/8
in. in diameter; jib halyards, 1/4 in. in diameter.

The main sheet rigging is 9/16-in. Russian bolt rope; jibs,
7/16-in. manila bolt rope, 4-strand; jib-sheet, 3/8-in. manila
bolt rope. Four 1/2-in. bronze turnbuckles, Fig. 34, are used for
the shrouds; one 5/8-in. turnbuckle for the jibstay and one for
the bobstay; four 3/8-in. turnbuckles for the runner plank stays,
and one for the martingale stay.

Two rope blocks for 3/8-in. wire rope, Fig. 10, are used for the
peak and throat, and one block for the wire rope 1/4 in. in
diameter for the jib halyard. Four 6-in. and one 7-in. cleats,
Fig. 18, are used. The blocks shown in Fig. 11 are used for the
main and jib sheets. The steering arrangement is shown in Figs. 4
and 5. The tiller is 3-1/2 ft. long; rudder post, 1-1/4 in. in
diameter; shoulder to lower end of jaws, 4 in.; depth of jaws,
2-7/8 in.; length of post including screw top, 12 in. The rubber
washer acts as a spring on rough ice.

In Figs. 13, 14, 15 and 16 are shown metal bands for the nose of
the backbone, and Figs. 19, 20, 21, 22 and 23 show the saddles
that fit over the backbone and hold the runner plank in place.
There are two sets of these. A chock should be sunk in the runner
plank at each side to connect with the backbone to keep it from
slipping sidewise as the boat rises in the air. The martingale
spreader is shown in Figs. 24 and 25. Straps through which the
ring bolts for the shrouds pass on the ends to fasten the
turnbuckles for the runner plank guys are shown in Figs. 26 and
27. The bobstay spreaders are shown in Figs. 28, 29 and 30. In
Fig. 31 is shown the top plate for the rudder post and in Figs. 32
and 33, the lower plate for same. The mast step is shown in Figs.
35, 36 and 37. Two positions of the jib traveler are shown in Fig.
38. The anchor plate for the bobstay under the cockpit is shown in
Figs. 39 and 40.

At the nose and heel the runner plank guys end in a loop. The
bobstay has a loop at the nose and ends in a turnbuckle that
fastens to the anchor plate under the cockpit, aft. The shrouds,
jibstay and martingale have loops at the masthead and are spliced
bare over solid thimbles. The loops are finished in pigskin and
served with soft cotton twine over the splice and varnished. The
parceling is done with insulating tape. Serve the tiller with soft
cotton twine and ride a second serving over the first. For the
halyards hoisting use a jig shown in Fig. 46. The thimble shown in
Fig. 47 is made by splicing the rope to the thimble at running
part of halyard and passing back and forth through cleat and
thimble. This gives a quick and strong purchase and does away with
cumbersome blocks of the old-fashioned jig. The jib-sheet leads
aft to the steering cockpit. The main-sheet ends in a jig of a
single block and a single block with becket. Be sure that your
sail covers are large enough--the sail maker always makes them too
tight. The cockpit covers must fit tightly around the cockpit
rail. Many boats have sail and cockpit covers in one piece.

The woodwork may be finished as desired by the builder. The
dimensions of the sails are given in the general drawing, Fig. 1.



** Turning Lights On and Off from Any Number of Places [310]

This can be done by the use of any number of reversing switches
such as

[Illustration: Wiring Diagram]

those shown at Band C. These are inserted between the two-way
switches A and D. Turning such a switch up or down connects the
four contact pieces either diagonally as at C, or lengthwise as at
B. The diagram shows connection from A to D, when the lamps will
be on, but by turning either of these four switches into its
alternative position, shown by the dotted lines, the circuit will
be broken and the lights extinguished. When this has been done,
the circuit may be restored and the lamps lighted again by
altering either of the four switches in exactly the same way, and
so on.

It will be observed that a reversing switch used in this way
practically undoes whatever is done by the other switches. In the
accompanying diagram only two reversing switches are shown and the
lights can be independently controlled from four distinct
positions. Any number of reversing switches can be placed between
the two-way switches A and D to increase the number of places from
which the lights could be turned on and off.
--Contributed by J. S. Dow, Mayfield, London.



** How to Make an Electric Pendant Switch [310]

It is often desired to use a pendant switch for controlling
clusters of incandescent lamps. When such a switch is not at hand,
a very good substitute can be made by screwing a common fuse plug
into a key socket and connecting the socket in series with the
lamps to be controlled. In this way you get a safe, reliable,
fused switch.
--Contributed by C. C. Heyder, Hansford, W. Va.



** Measure [310]

Never guess the length of a piece of work--measure it.



** Home-Made Water Motor  [311]

The small water motor shown in the illustration is constructed in
the same manner as a German toy steam turbine. The wheel, which is
made of aluminum 1/16 in. thick and 7 in. in diameter, has 24
blades attached to it.

The lugs or extensions carrying the rim must be made from the
metal of the wheel, therefore a circle 8 in. in diameter must be
first described on the aluminum plate, then another circle 7 in.
in diameter within the first and then a circle for the base of the
blades, 3-1/2 in. in diameter. Twenty-four radial lines at equal
distances apart are drawn between the two smaller circles and a
1/4-in. hole drilled at the intersecting points of the radial
lines and the innermost circle.

Centrally between each pair of radial lines and between the two
outer circles, 1/2 by 3/8-in. lugs are marked out and the metal
cut away as shown in Fig. 1. A 1/8-in. hole is then drilled in the
center of each lug. Each division is separated by cutting down
each radial line to the 1/4-in. hole with a hacksaw. Each arm is
then given a quarter turn, as shown by the dotted lines in Fig. 2,
and the lug bent over at right angles to receive the rim. The rim
is made of the same material as the disk and contains twenty-four
1/8 in. holes corresponding to those in the lugs to receive brass
bolts 1/4-in. long.

The disks PP were taken from the ends of a discarded typewriter
platen, but if these cannot be readily obtained, they can be
turned from metal or a heavy flat disk used instead.

The casing was made from two aluminum cake pans whose diameter was
8 in. at the base, increasing to 9 in. at the rim. The centers of
these were located and a 1/4-in. hole drilled for the

[Illustration: Fig. 3]

shaft. The disks P are the same as used on the wheel. Six holes
1/8-in. in diameter were drilled through the flat part of the rims
while the two halves were held together in a vise. Bolts were
placed through these holes to join the casing when ready for
assembling. One side of the casing was then bolted to two 4-in.
ordinary metal shelf brackets which were

[Illustration: Details of Motor]

screwed to a substantial wood base. This kept one-half of the
casing independent of the main structure so that the wheel is
easily accessible.

The nozzle was made of 1/2-in. brass pipe which was first filled
with molten babbitt metal. When the metal was cool, a 1/4-in. hole
was drilled halfway through the length of the tube, the hole being
continued through to the other end by means of a 1/8-in. drill.
The lower orifice was then slightly enlarged with a small taper
reamer, and the upper portion of the bore was reamed out almost to
the brass to make a smooth entrance for the water.

A fixture to hold this nozzle is shown in Fig. 3. It was cast of
babbitt metal in a wood mold. The hole for the nozzle was drilled
at an angle of 20 deg. to the plate part. An alternative and
perhaps easier way would be to insert the nozzle in the mold at
the proper angle and cast the metal around it. A hole was then cut
in one of the sides of the casing at a point 2-7/8 in. along a
horizontal line from the center. The nozzle fixture was then
bolted on with the exit orifice of the nozzle pointing downward
and through the hole in the casing.

Six 1/8-in. holes were drilled through the flat portions of the
rims while the two halves of the casing were held securely
together in a vise. Bolts were used in these holes to join the
casing.

The wheel was used on the dripboard of a kitchen sink and no
provision was made to carry off the spent water except to cut two
1/2-in. holes in the bottom of the casing and allowing the waste
to flow off directly into the sink.
--Contributed by Harry F. Lowe, Washington, D. C.



** Device for Baseball Throwing Practice [312]

Anyone training to be a baseball player will find the device shown
in the accompanying illustration a great help

[Illustration: Ball Bounding on Concrete Slabs]

when practicing alone. It consists of two cement slabs, one flat
and upright, the other curved and on the ground. The vertical slab
is fastened securely against a fence, barn or shed. The barn or
the shed is preferable, for if the slab is fastened to a fence,
the ball will bound over a great many times and much time will be
lost in finding it.

The player stands as far as he cares from the slabs and throws the
ball against the lower slab. The ball immediately rebounds to the
upright slab and returns with almost as great a force as it was
delivered. If the thrower does not throw the ball exactly in the
same spot each time, the ball will not rebound to the same place,
consequently the eye and muscles are trained to act quickly,
especially if the player stands within 15 or 20 ft. of the slabs
and throws the ball with great force.

This apparatus also teaches a person to throw accurately, as a
difference in aim of a few inches on the lower slab may cause the
ball to flyaway over the player's head on the rebound.
--Contributed by F. L. Oilar, La Fayette, Indiana.



** How to Mail Photographs [312]

Cut a piece of cardboard 1 in. longer and 1 in. wider than the
mount of the photograph and lay the picture on it in the center.
This allows a 1/2-in. border on all sides of the photograph. Punch
two holes 1 in. apart at A, B, C and D, Fig. 1, in the cardboard
border close to the edge of the picture. Put a string up through
the hole B, Fig. 2, then across the corner of the photograph and
down through the hole C and up through hole D, then to E, etc.,
until the starting point A is reached, and tie the ends.

The photograph will not get damaged, if it is covered with tissue
paper and placed with the face to the cardboard. The extension
border of cardboard prevents the edges of the mount from being
damaged and the corners

[Illustration: Back for Mailing Photo]

from wearing. Both cardboard and photograph are wrapped together
in paper, and the package is ready for mailing.
--Contributed by Earl R. Hastings, Corinth, Vt.



** A Mystifying Watch Trick [313]

Borrow a watch from one of the audience and allow the owner to
place it in the box, as shown in Fig. 1. This box should be about
3 in. long, 4 in. wide and 2-1/2 in. deep, says the Scientific
American. It should be provided with a hinged cover, M, with a
lock, N. The tricky part of this box is the side S, which is
pivoted at T by driving two short nails into it, one through the
front side and the other through the back, so that when S is
pushed in at the top, it swings around as shown in Fig. 1 and
allows the watch to slide out into the performer's hand. The side
S should fit tightly when closed, so that the box may be examined
without betraying the secret. As the side S extends down to the
bottom of the box, it facilitates the use of the fingers in
pulling outward at the lower pan while the thumb is pressing
inward at the top part. The side of the box opposite S should be
built up in the same way, but not pivoted.

Use a flat-bottom tumbler, A, Fig. 2, containing an inner cone, B,
for the reproduction of the watch. The cone is made of cardboard
pasted together so it fits snugly inside of the tumbler. The cone
is closed except at the bottom, then bran is pasted on the outside
surfaces to make the tumbler appear as if filled with bran when it
is in place. Place the tumbler with the cone inside on a table
somewhat in the background. Put some loose bran on top of the cone
and allow the cork, attached as shown in B, Fig. 2, to hang down
on the outside of the tumbler, away from the audience. A large
handkerchief should be laid beside the tumbler.

After the watch has been placed in the box, Fig. 1, the performer
takes the box in his left hand, and while in the act of locking it
with his right hand secures possession of the watch as previously
explained. Tossing the key to the owner of the watch, the
performer places the box on a chair or table near the audience
and, with the watch securely palmed, walks back to get the
tumbler. Standing directly in front of the tumbler with his back
toward the audience, the performer

[Illustration: Parts for the Watch Trick]

quickly raises the cone with his right hand, lays the watch in the
bottom of the tumbler and replaces the cone.

The loaded tumbler and the handkerchief are then brought forward,
and the former is placed in full view of the audience with the
cork hanging down behind it. The performer calls attention to the
tumbler being full of bran and picks up some of it from the top to
substantiate his statement. He then spreads the handkerchief over
the tumbler, commands the watch to pass from the box into the
tumbler and the bran to disappear.

The box is then handed to the owner of the watch so that he may
unlock it with the key he holds. As soon as the box is found to be
empty, the performer grasps the handkerchief spread over the
tumbler, also the cork tied to the cone. Raising the handkerchief,
he carries up the cone within it, leaving the watch in the bottom
to be returned to its owner.



** Locking Several Drawers with One Lock [314]

A series or row of drawers can be secured with one lock by using
the

[Illustration: Drawer Lock]

device shown in the sketch. This method takes away several
dangling locks and the carrying of many keys. A rod is used
through the various staples over the hasps. The rod is upset on
one end and flattened to make sufficient metal for drilling a hole
large enough to insert the bar of a padlock. If the bar is made of
steel and hardened, it is almost impossible to cut it in two.
--Contributed by F. W. Bentley, Huron, S. Dak.



** Testing Small Electric Lamps [314]

The accompanying sketch shows the construction of a handy device
for testing miniature electric lights. The base is made to take in
an electric flash lamp battery. Two strips of brass, C and D, are
connected to the battery. The lamp is tested by

[Illustration: Lamp Tester]

putting the metal end on the lower brass strip and the side
against the upper one. A great number of lamps can be tested in a
short time by means of this device.
--Contributed by Abner B. Shaw, North Dartmouth, Mass.



** How to Make a Pin Ball [314]

The pin ball shown in the illustration is made of calfskin
modeling leather and saddler's felt. Two pieces of leather are
used, and one piece of felt, all three being cut circular to a
diameter of about 3 in. The felt may be about 1/2 in. thick, and
leather of a deep brown color is recommended.

Moisten the leather on the back side with as much water as it will
take without showing through the face. Lay it on a sheet of heavy
glass or copper, or other hard, smooth, nonabsorbent material.
Place the design, which has been previously prepared, over the
face of the leather. Indent the outline of the design with a
nutpick or any other pointed tool that will not cut the leather.
Remove the pattern, and go

[Illustration: Made of Leather and Felt]

over the outline again to deepen the tool marks.

The space between the border and the design is now stamped with a
cuppointed nail set, care being taken not to cut the leather,
especially if the tool be new. Rubbing the edges of the nail set
over a piece of emery paper will serve to dull them, if they are
too sharp.

When the designs have been worked on the leather, paste or glue
the leather to the two sides of the belt, and punch a hole in the
center through which to place a cord for hanging up the ball.



** Cleaning Woodwork [315]

An easy method of removing the dirt and old varnish at the same
time around a kitchen sink is told by a correspondent of National
Magazine as follows:

Make a soft soap from common yellow laundry soap, and when it is
almost cold stir in one tablespoonful of concentrated lye and
one-half cupful of kerosene. When the mixture becomes a heavy
paste, it is ready to be spread over the woodwork with a paint
brush. Allow the soap to remain for a day and a half, then wash it
off with plenty of hot water. The woodwork will be clean and ready
for varnishing when it dries out.



** Bill File Made of Corkscrews [315]

An ordinary corkscrew makes a convenient file for small bills or
memoranda. It may be thrown in any position without danger of the
papers slipping off. A rack to hold a number of files can be made
of a wood strip (Fig. 1) fitted with hooks or screw eyes cut in a
hook shape, as shown in Fig. 2,

[Illustration: Bill File]

Single bills may be separated from the others and will remain
separated as in Fig. 3.
--Contributed by James M. Kane, Doylestown, Pa.



** Ornamental Metal Inkstand [315]

The metal required for making this stand is 3/16 in. in width and
may be

[Illustration: Inkstand and Details of Frame]

steel, brass or copper. The shaping is done as shown in Figs. 2
and 3. There are, in all, eight pieces to be bent. The two
supports are each formed of one piece of metal with the exception
that the end scroll pieces on the under side are made separately.
Eight rivets are required to fasten the two horizontal rings to
the supports. The glass receptacle can be purchased at a
stationery store.



** Holding Eyeglasses Firm [315]

Persons who wear noseglasses and who are troubled with excessive
perspiration, should chalk the sides of the bridge of the nose
before putting on the glasses. The latter will then never slip,
even in the warmest weather. If the chalk shows, use a pink stick,
which can be purchased from any art school or supply store.

Substitute for Gummed Paper [315]

Gummed paper is a great convenience in the home especially for
labels, but it is not always found among the household supplies.
The gummed portions of unsealed envelopes in which circulars are
received can be utilized for this purpose. Quite a large label may
be made from these envelope flaps.



** Repairing a Broken Phonograph Spring  [316]

As I live a great distance from a railroad station, I did not care
to pay the price, and await the time necessary to deliver a new
phonograph spring to replace one that broke in my machine, and I
repaired the old one in a creditable manner as follows:

I forced the two ends of the break out where I could get at them,
then heated each end separately with a pair of red hot tongs and
turned a hook or lap on them the same as the joints in knock-down
stovepipes. When the ends were hooked together, the spring worked
as good as new. The heated portion did not affect the strength of
the spring.
--Contributed by Marion P. Wheeler, Greenleaf, Oregon.



** Calls While You Are Out [316]

If you wish to know whether or not the door or telephone bell
rings during your absence, place a little rider of paper or
cardboard on the clapper in such a way that it will be dislodged
if the bell rings.



** A Small Bench Lathe Made of Pipe Fittings [316]

The most important machine in use in the modern machine or
wood-working shop is the lathe. The uses to which this wonderful
machine can be put would be too numerous to describe, but there is
hardly a mechanical operation in which the turning lathe does not
figure. For this reason every amateur mechanic and wood-worker who
has a workshop, no matter how small, is anxious to possess a lathe
of some

[Illustration: Fig. 1-Details of Lathe]

sort. A good and substantial homemade lathe, which is suitable for
woodturning and light metal work, may be constructed from pipe and
pipe fittings as shown in the accompanying sketch.

The bed of this lathe is made of a piece of  1-in. pipe, about 30
in. long. It can be made longer or shorter, but if it is made much
longer, a larger size of pipe should be used. The head-stock is
made of two tees, joined by a standard long nipple as shown in
Fig. 1. All the joints should be screwed up tight and then
fastened with 3/16-in. pins to keep them from turning. The ends of
the bed are fixed to the baseboard by means of elbows, nipples and
flanges arranged as shown. The two bearings in the headstock are
of brass. The spindle hole should be drilled and reamed after they
are screwed in place in the tee. The spindle should be of steel
and long enough to reach through the bearing and pulley and have
enough end left for the center point. The point should extend
about 1-1/2 in. out from the collar. The collar can be turned or
shrunk on the spindle as desired. The end of the spindle should be
threaded to receive a chuck.

The tailstock is also made of two tees joined by a nipple. The
lower tee should be bored out for a sliding fit on the bed pipe.
The upper one should be tapped with a machine tap for the spindle
which is threaded to fit it. The

[Illustration: Fig. 2]

spindle has a handle fitted at one end and has the other end bored
out for the tail stock center. Both the tail stock and the
headstock centerpoints should be hardened. A clamp for holding the
tail stock spindle is made of a piece of strap iron, bent and
drilled as shown. It is held together by means of a small machine
screw and a knurled nut. The tee should have a slot cut in it
about one-half its length and it should also have one bead filed
away so that the clamp will fit tightly over it.

The hand rest is made from a tapering elbow, a tee and a forging.
The forging can be made by a blacksmith at a small expense. Both
the lower

[Illustration: Fig. 3]

tees of the handrest and the tailstock should be provided with
screw clamps to hold them in place.

The pulley is made of hardwood pieces, 3/4 or 1 in. thick as
desired. It is fastened to the spindle by means of a screw, as
shown in Fig. 2, or a key can be used as well.

Care must be taken to get the tailstock center vertically over the
bed, else taper turning will result. To do this, a straight line
should be scratched

[Illustration: Fig. 4-Chuck ]

on the top of the bed pipe, and when the tail stock is set exactly
vertical, a corresponding line made on this. This will save a
great deal of time and trouble and possibly some errors.

The two designs of chucks shown in Figs. 3 and 4 are very easy to
make, and will answer for a great variety of work.

As the details are clearly shown and the general dimensions given
on the accompanying sketches, it should not be a difficult matter
for the young mechanic to construct this machine.
--Contributed by W. M. Held, Laporte, Indiana.



** Holder for Flexible Lamp-Cord [317]

The holder is made of a round stick--a piece of a broom handle
will do--as shown in Fig. 1. It is about 1 in. long with two
notches cut out for the strands of the cord. These holders are
easily made and will answer the purpose almost as well as the ones
made in porcelain. Painting or enameling will improve not only
their appearance, but also their insulating properties.

[Illustration: Ceiling-Cord Holder]

Several of them can be used along a line, as shown in Fig. 2.
--Contributed by M. Musgrove, Boissevain, Man.



** Support for Double Clotheslines [318]

Anyone using a double clothesline over pulleys will find the
arrangement shown in Fig. 1 for supporting the

[Illustration: Holder on a Clothesline]

lower line quite convenient. The support is made of a piece of
3/4-in. square or round wood which has a screw-eye turned into
each end. The line is run through these screw-eyes as shown in
Fig. 2.
--Contributed by W. W. UpDeGraff, Fruitvale, Cal.



** Hot Pan or Plate Lifter  [318]

Unless a person uses considerable caution, bad burns may be
suffered when taking hot pies from an oven. If one reaches in and
takes hold of the pie pan with a cloth, the arm is liable to touch
the oven door and receive a

[Illustration: Lifter on Pie Pan]

burn. To obviate this, I made the device shown in the sketch for
lifting hot pie pans and plates. The handle is of pine about 18
in. long, and the two loops are made of heavy wire. The ends of
the first loop of wire are put through the handle from the back,
as shown, and then bent so as to stand out at an angle. The second
loop is hinged to swing free on the opposite side of the handle.
In use, the hinged side of the loop is dropped under one edge of a
plate or pan and the rigid loop is then hooked under the opposite
side. The weight of the pan or dish draws the loops together and
there is little or no danger of a spill. The same lifter will pick
up any size of plate or pan from a saucer to the largest pie
plates.
--Contributed by E. J. Cline, Ft. Smith, Ark.



** Weighting Indian Clubs  [318]

An ordinary Indian club can be fixed so that different weights may
be had

[Illustration: Indian Club]

without changing clubs. Each club is bored to receive lead washers
which are held in place by a spiral spring. A bolt is run through
from the handle end and fastened with a round nut. The lead
washers and spring slip over the bolt as shown in the
illustration. Changing the number of washers changes the weight of
the club.
--Contributed by Walter W. White, Denver, Colo.



** Venting a Funnel  [318]

When using a tight-fitting funnel in a small-neck bottle, trouble
is usually experienced by the air causing a spill. This can be
easily remedied by splitting a match in half and tying the parts
on the sides of the stem with thread.
--Contributed by Maurice Baudier, New Orleans, La.



** Lubricating Woodscrews [318]

A screw may be turned into hardwood easily, by boring a small hole
and lubricating the screw threads with soft soap.



** To Make "Centering" Unnecessary [319]

For drilling a hole in a chucked piece, centering is just one
operation too many, if this method is followed:

First, face off the end of the piece, making a true spot at least
as big as the diameter of the drill. Put a center punch mark where
the tool lines indicate the center of revolution. This serves as a
rough guide for placing the drill between the tail stock center
and the work as usual. Clamp a tool in the tool-post and, on
starting the lathe, bring it in contact with the drill and keep it
firmly so until the drill is in fully up to the lips. This
prevents the drill from wobbling, and when once in true up to its
size, it cannot change any more than under any other starting
conditions. After being entered, the drill does not need the tool,
which should be backed out of contact.



** Fountain Pen Cap Used as a Ruler [319]

When it is necessary to draw a short line and there is no ruler at
hand, take

[Illustration: Ruling Lines]

off the cap of your fountain pen and use it as a ruler. If the cap
is fitted with a retaining clip, all the better, as this will
prove a safeguard against slipping.



** Vanishing Handkerchief Trick [319]

The necessary articles used in performing this trick are the
handkerchief, vanishing wand, a long piece of glass tubing, a bout
1/2 in. shorter t h a n the wand, and a paper tube closed at one
end and covered with a cap at the other, says the Sphinx. The
handkerchief rod, shown at C, is concealed in the paper tube A
before the performance. The glass tube B, after being shown empty;
is put into the paper tube A, so that the handkerchief rod now is
within it, unknown to the spectators. The handkerchief is then
placed over

[Illustration: Wand]

the opening of the tube and pushed in by means of the wand. In
doing this, the handkerchief and the rod are pushed into the wand,
as shown in D. After the wand is removed, the cap is placed over
the paper tube, and this given to someone to hold. The command for
the handkerchief to vanish is given, and it is found to be gone
when the glass tube is taken out of the paper cover. This is a
novel way of making a handkerchief vanish. It can be used in a
great number of tricks, and can be varied to suit the performer.



** Removing Glass Letters from Windows [319]

Glass letters are removed in the same way as metal letters, by
applying caustic soda or potash around the edges of the letters.
As the cement softens, manipulate the point of a pocket knife
under the edges of the letter until the caustic works completely
under and makes it easy to lift the letters. With care and
patience, every letter may be thus taken off without breakage.



** A Guitar That Is Easy to Make [320]

A guitar having straight lines, giving it an old-fashioned
appearance, can be made by the home mechanic, and if care is taken
in selecting the material, and having it thoroughly

[Illustration: Details of Guitar]

seasoned, the finished instrument will have a fine tone. The
sides, ends and bottom are made of hard wood, preferably hard
maple, and the top should be made of a thoroughly seasoned piece
of soft pine. The dimensioned pieces required are as follows:

1 Top. 3/16. by 14 by 17 in. 1 Bottom. 3/16 by 14 by 17 in. 2
Sides. 3/16 by 3-5/8 by 16-3/4 in. 1, End. 3/16 by 3-5/8 by 13-1/8
in. 1 End. 3/16 by 3-5/8 by 9-5/6 in. 1 Neck. 1 by 2-5/16 by
18-1/2 in. 1 Fingerboard 5/16 by 2-5/8 by 16 in.

Cut the fingerboard tapering and fasten pieces cut from hatpins
with small wire staples for frets. All dimensions for cutting and
setting are shown in the sketch. The neck is cut tapering from G
to F and from J to F, with the back side rounding. A drawknife is
the proper tool for shaping the neck. Cut a piece of hard wood,
1/4 in. square and 1-7/8 in. long, and glue it to the neck at F.
Glue the fingerboard to the neck and hold it secure with clamps
while the glue sets.

The brace at D is 1 in. thick, cut to any shape desired. The sides
are glued together and then the front is glued on them. Place some
heavy weights on top and give the glue time to dry. Fasten pieces
of soft wood in the corners for braces. Glue the neck to the box,
making it secure by the addition of a carriage bolt at A. A small
block C is glued to the end to reinforce it for the bolt. Glue
strips of soft wood, as shown by K, across the front and back to
strengthen them. The back is then glued on and the outside
smoothed with sandpaper.

Make the bottom bridge by using an old hatpin or wire of the same
size for E secured with pin staples. Glue the bridge on the top at
a place that will make the distance from the bridge F to the
bottom bridge E just 24 in. This dimension and those for the frets
should be made accurately. Six holes, 3/16 in. in diameter, are
drilled in the bottom bridge for pins. The turning plugs B and
strings can be purchased at any music store.
--Contributed by J. H. Stoddard, Carbondale,Pa.



** Greasing the Front Wheels of an Automobile [320]

The front wheel bearings of an automobile can be greased without
removing the wheels in the following manner: Remove the hub caps
and fill them with heavy grease and then screw them in place.
Continue this operation until the grease is forced between all the
bearings and out through the small clearance on the opposite side
of the wheels. This should be done at least once every month to
keep bearings well lubricated and free from grit. Dirt cannot
enter a well filled bearing as easily as muddy water can enter a
dry bearing.
--Contributed by Chas. E. Frary, Norwalk, O.



** Removing Mold [320]

Mold on wallpaper can be removed at once by applying a solution of
1 part salicylic acid in 4 parts of 95% alcohol.



** HOW TO MAKE A PAPER BOAT [321]
A Light Boat That Can Be Easily Carried

[Illustration: The Paper Boat Is Light and Easy to Propel]

Now you might think it absurd to advise making a paper boat, but
it is not, and you will find it in some respects and for some
purposes better than the wooden boat. When it is completed you
will have a canoe, probably equal to the Indian's bark canoe. Not
only will it serve as an ideal fishing boat, but when you want to
combine hunting and fishing you can put your boat on your
shoulders and carry it from place to place wherever you want to go
and at the same time carry your gun in your hand. The material
used in its construction is inexpensive and can be purchased for a
few dollars.

Make a frame (Fig. 1) on which to stretch the paper. A board 1 in.
thick and about 1 ft. wide and 11-1/2 ft. long is used for a keel,
or backbone, and is cut tapering for about a third of its length,
toward each end, and beveled

[Illustration: Detail of Framework Construction]

on the outer edges (A, Fig. 2). The cross-boards (B, B, Fig. 2)
are next sawed from a pine board 1 in. thick. Shape these as shown
by A, Fig. 4, 13 in. wide by 26 in. long, and cut away in the
center to avoid useless weight. Fasten them cross-wise to the
bottom board as shown in Fig. 1 and 2, with long stout screws, so
as to divide the keel into three nearly equal parts. Then add the
stem and stern pieces (C, C, Fig. 2). These are better, probably,
when made of green elm. Screw the pieces to the bottom-board and
bend them, as shown in Fig. 2, by means of a string or wire,
fastened to a nail driven into the bottom. Any tough, light wood
that is not easily broken when bending will do. Green wood is
preferable, because it will retain the shape in which it has been
bent better after drying. For the gunwales (a, a, Fig. 3), procure
at a carriage factory, or other place, some tight strips of ash,
3/8 in. thick. Nail them to the crossboards and fasten to the end
pieces

[Illustration: Important Features of Construction]

(C, C,) in notches, by several wrappings of annealed iron wire or
copper wire, as shown in Fig. 3. Copper wire is better because it
is less apt to rust. For fastening the gunwales to the crossboards
use nails instead of screws, because the nails are not apt to
loosen and come out. The ribs, which are easily made of long,
slender switches of osier willow, or similar material, are next
put in, but before doing this, two strips of wood (b, b, Fig. 3)
should be bent and placed as in Fig. 3. They are used only
temporarily as a guide in putting in the ribs, and are not
fastened, the elasticity of the wood being sufficient to cause
them to retain their position. The osiers may average a little
more than 1/2 in. in thickness and should be cut, stripped of
leaves and bark and put in place while green and fresh. They are
attached to the bottom by means of shingle nails driven through
holes previously made in them with an awl, and are then bent down
until they touch the strips of ash (b, b, Fig. 3), and finally cut
off even with the tops of the gunwales, and notched at the end to
receive them (B, Fig. 4). Between the cross-boards the ribs are
placed at intervals of 2 or 3 in., while in other parts they are
as much as 5 or 6 in. apart. The ribs having all been fastened in
place as described, the loose strips of ash (b, b, Fig. 3) are
withdrawn and the framework will appear somewhat as in Fig. 1. In
order to make all firm and to prevent the ribs from changing
position, as they are apt to do, buy some split cane or rattan,
such as is used for making chair-bottoms, and, after soaking it in
water for a short time to render it soft and pliable, wind it
tightly around the gunwales and ribs where they join, and also
interweave it among the ribs in other places, winding it about
them and forming an irregular network over the whole frame. Osiers
probably make the best ribs, but twigs of some other trees, such
as hazel or birch, will answer nearly as well. For the ribs near
the middle of the boat, twigs 5 or 6 ft. long are required. It is
often quite difficult to get these of sufficient thickness
throughout, and so, in such cases, two twigs may be used to make
one rib, fastening the butts side by side on the bottom-board, and
the smaller ends to the gunwales, as before described. In drying,
the rattan becomes very tight and the twigs hard and stiff.

The frame-work is now complete and ready to be covered. For this
purpose buy about 18 yd. of very strong wrapping-paper. It should
be smooth on the surface, and very tough, but neither stiff nor
very thick. Being made in long rolls, it can be obtained in almost
any length desired. If the paper be 1 yd. wide, it will require
about two breadths to reach around the frame in the widest part.
Cut enough of the roll to cover the frame and then soak it for a
few minutes in water. Then turn the frame upside down and fasten
the edges of the two strips of paper to it, by lapping them
carefully on the under side of the bottom-board and tacking them
to it so that the paper hangs down loosely on all sides. The paper
is then trimmed, lapped and doubled over as smoothly as possible
at the ends of the frame, and held in place by means of small
clamps. It should be drawn tight along the edges, trimmed and
doubled down over the gunwale, where it is firmly held by slipping
the strips of ash (b, b) just inside of the gunwales into notches
which should have been cut at the ends of the cross-boards. The
shrinkage caused by the drying will stretch the paper tightly over
the framework. When thoroughly dry, varnish inside and out with
asphaltum varnish thinned with turpentine, and as soon as that has
soaked in, apply a second coat of the same varnish, but with less
turpentine; and finally cover the laps or joints of the paper with
pieces of muslin stuck on with thick varnish. Now remove the loose
strips of ash and put on another layer of paper, fastening it
along the edge of the boat by replacing the strips as before. When
the paper is dry, cover the laps with muslin as was done with the
first covering. Then varnish the whole outside of the boat several
times until it presents a smooth shining surface. Then take some
of the split rattan and, after wetting it, wind it firmly around
both gunwales and inside strip, passing it through small holes
punched in the paper just below the gunwale, until the inside and
outside strips are bound together into one strong gunwale. Then
put a piece of oil-cloth in the boat between the cross-boards,
tacking it to the bottom-board. This is done to protect the bottom
of the boat.

Now you may already have a canoe that is perfectly water-tight,
and steady in the water, if it has been properly constructed of
good material. If not, however, in a few days you may be
disappointed to find that it is becoming leaky. Then the best
remedy is to cover the whole boat with unbleached muslin, sewed at
the ends and tacked along the gunwales. Then tighten it by
shrinking and finally give it at least three coats of a mixture of
varnish and paint. This will doubtless stop the leaking entirely
and will add but little to either the weight or cost.

Rig the boat with wooden or iron row locks (B, B, Fig. 5),
preferably iron, and light oars. You may put in

[Illustration: Off for a Hunt]

several extra thwarts or cross-sticks, fore and aft, and make a
movable seat (A, Fig. 5.) With this you will doubtless find your
boat so satisfactory that you will make no more changes.

For carrying the boat it is convenient to make a sort of short
yoke (C, Fig. 5), which brings all the weight upon the shoulders;
and thus lightens the labor and makes it very handy to carry.



** To Hang Heavy Things on a Nail [323]

Boys will find many places around

[Illustration: Double Nails]

the house, where a hook to hang things on will be a great
convenience. Instead of buying hooks use wire nails, and if driven
as shown in the cut, they will support very heavy weights. Drive
the lower nail first.



** A Home-Made Elderberry Huller [324]

As we had only one day to pick elderberries, we wanted to get as
many of them as we could in that time. We could pick them faster
than they could

[Illustration: Details of the Elderberry Huller]

be hulled by hand so we made a huller to take along with us to
hull the berries as fast as they were picked. We procured a box
and made a frame, Fig. 1, to fit it easily, then made another
frame the same size and put a piece of wire mesh between them as
shown in Fig. 2, allowing a small portion of the mesh to stick out
of the frames. The top frame would keep the berries from rolling
or jumping off, and the bottom frame kept the wire mesh and frame
from being shaken off the box. The projecting edges of the mesh
would keep the frame on the top edge of the box. The top view of
the frame is shown in Fig. 1 and the end in Fig. 5, and the box on
which the frame rests in Fig. 3. The actual size of the wire mesh
used is shown in Fig. 4. One person could hull with this huller as
many berries as two persons would pick.
--Contributed by Albert Niemann, Pittsburg, Pa.



** How to Make a Bulb on a Glass Tube [324]

As a great many persons during the winter months are taking
advantage of the long evenings to experiment in one way or
another, the following method of forming bulbs on glass tubes may
be of interest. A common method is to heat the part to be formed
and by blowing in one end of the tube gradually expand the glass.
This way has its drawbacks, as many are not sufficiently familiar
with the work to blow a uniform blast, and the result is, a hole
is blown through the side of the tube by uneven heating or
blowing.

A good way to handle this work, is to take the tube and 1 or 2 in.
more in length than the finished article is to be and place one
end over an alcohol flame, and by holding a spare piece of tubing
against the end allow them both to come to a melting heat, then
pull apart and instead of breaking off the long thread thus
formed, simply hold it in the flame at an angle of 45 deg. and
melt it down and close the end at the same time. Close the other
end with the same operation; this makes the tube airtight.

Gradually heat the tube at the point where the bulb is to be
formed, slowly turning the tube to get a uniform heat. The air
inside of the tube becoming heated will expand, and the glass,
being softer where the flame has been applied, will be pushed out
in the shape of a bulb. A great deal of care should be taken not
to go to extremes, as the bulb will burst with a loud report if
the heat is applied too long. The best results are obtained by
heating the glass slowly and then the bulb can be formed with
regularity. This is an easy way to make a thermometer tube. After
the bulb is formed, the other end of the tube can be opened by
heating, drawing out and breaking the thread like glass.
--Contributed by A. Oswald.



** How to Make a Sconce [325]

A sconce is a candlestick holder, so made that it has a reflector
of brass or copper and is to hang upon the wall. The tools
necessary are a riveting hammer, file, metal shears, rivet punch,
flat and round-nosed pliers, screwdriver and sheet brass or copper
No. 23 gauge.

To make the sconce proceed as follows: First, cut off a piece of
brass so that it shall have 1/2 in. extra metal all around;
second, with a piece of carbon paper, trace upon the brass lines
that shall represent the margin of the sconce proper, also trace
the decorative design; third, with a nail set make a series of
holes in the extra margin about 3/4 in. apart and large enough to
take in a 3/4-in. thin screw; fourth, fasten the metal to a thick
board by inserting screws in these holes; fifth, with a
twenty-penny wire nail that has had the sharpness of its point
filed off, stamp the background of the design promiscuously. By
holding the nail about 1/4 in. above the work and striking it with
the hammer, at the same time striving to keep its point at 1/4 in.
above the metal, very rapid progress can be made. This stamping
lowers the background and at the same time raises the design.
Sixth, chase or stamp along the border of the design and
background using a nail filed to a chisel edge. This is to make a
clean sharp division between background and design. Seventh, when
the stamping is complete remove the screws and metal from the
board and cut off the extra margin with the metal shears. File the
edges until they are smooth to the touch.

The drip cup is a piece of brass cut circular and shaped by
placing the brass over a hollow in one end of a block. Give the
metal a circular motion, at the same time beat it with a
round-nosed mallet. Work from the center along concentric rings
outward, then reverse.

The candle holders may have two, three, four, or six arms, and are
bent to shape by means of the round-nosed

[Illustration: Completed Sconce; Shaping the Holders; Riveting]

pliers. The form of the brackets which support the drip cups may
be seen in the illustration.

Having pierced the bracket, drip cup, and holder, these three
parts are riveted together as indicated in the drawing. It will be
found easier usually if the holder is not shaped until after the
riveting is done. The bracket is then riveted to the back of the
sconce. Small copper rivets are used.

It is better to polish all the pieces before fastening any of them
together. Metal polish of any kind will do. After the parts have
been assembled a lacquer may be applied to keep the metal from
tarnishing.



** How To Make a Hectograph [326]

[Illustration: Making Copies with the Hectograph]

A hectograph is very simply and easily made and by means of it
many copies of writing can be obtained from a single original.
Make a tray of either tin or pasteboard, a little larger than the
sheet of paper you ordinarily use and about 1/2 in. deep. Soak 1
oz. of gelatine in cold water over night and in the morning pour
off the water. Heat 6-1/2 oz. of glycerine to about 200 deg. F. on
a water bath, and add the gelatine. This should give a clear
glycerine solution of gelatine.

Place the tray so that it is perfectly level and pour in the
gelatinous composition until it is nearly level with the edge of
the tray. Cover it so the cover does not touch the surface of the
composition and let it stand six hours, when it will be ready for
use.

Make the copy to be reproduced on ordinary paper with aniline ink;
using a steel pen, and making the lines rather heavy so they have
a greenish color in the light. A good ink may be made of methyl
violet 2 parts, alcohol 2 parts, sugar 1 part, glycerine 4 parts,
and water 24 parts. Dissolve the violet in the alcohol mixed with
the glycerine; dissolve the sugar in the water and mix both
solutions.

When the original copy of the writing is ready moisten the surface
of the hectograph slightly with a sponge, lay the copy face down
upon it and smooth down, being careful to exclude all air bubbles
and not shifting the paper. Leave it nearly a minute and raise one
corner and strip it from the pad, where will remain a reversed
copy of the inscription.

Immediately lay a piece of writing paper of the right size on the
pad, smooth it down and then remove as before. It will bear a
perfect copy of the original. Repeat the operation until the
number of copies desired is obtained or until the ink on the pad
is exhausted. Fifty. or more copies can be obtained from a single
original.

When through using the hectograph wash it off with a moist sponge,
and it will be ready for future use. If the surface is impaired at
any time it can be remelted in a water bath and poured into a tray
as before, if it has not absorbed too much ink.



** How to Make a Sailomobile [326]
By Frank Mulford, Shiloh, N. J.

I had read of the beach automobiles used on the Florida coast;
they were like an ice boat with a sail, except they had wheels
instead of runners. So I set to work to make something to take me
over the country roads.

I found and used seven fence pickets for the frame work, and other
things as they were needed. I spliced two rake handles together
for the mast, winding the ends where they came together with wire.
A single piece would be better if you can get one long enough. The
gaff, which is the stick to which the upper end of the sail is
fastened, is a broomstick. The boom, the stick at the bottom of
the sail, was made of a rake handle with a broomstick spliced to
make it long enough. Mother let me have a sheet, which I put down
on the floor and cut into the shape of a mainsail. The wind was
the cheapest power to be found, thus it was utilized; the three
wheels were cast-off bicycle wheels.

I steer with the front wheel, which was the front wheel of an old
bicycle with the fork left on. The axle between the rear wheels is
an iron bar which cost me 15 cents, and the pulley which raises
and lowers the sail cost 5 cents. Twenty cents was all I spent,
all the rest I found.

A saw, hammer, and brace and bit were the tools used. Slats made
the seat and a cushion from the house made it comfortable, and in
a week

[Illustration: Sailomobile for Use on Country Roads]

everything was ready for sailing.

Once it was started with only my little cousin in it and I had to
run fast to catch up.



** A Home-Made Magic Lantern [328]

The essential parts of a magic lantern are a condensing lens to
make the beam of light converge upon the slide to illuminate it
evenly, a projecting lens

[Illustration: Lantern House]

with which to throw an enlarged picture of the illuminated slide
upon a screen and some appliances for preserving the proper
relation of these parts to each other. The best of materials
should be used and the parts put together with care to produce a
clear picture on the screen.

The first to make is the lamp house or box to hold the light. Our
illustration shows the construction for an electric light, yet the
same box may be used for gas or an oil lamp, provided the material
is of metal. A tin box having dimensions somewhere near those
given in the diagrammatic sketch may be secured from your local
grocer, but if such a box is not found, one can be made from a
piece of tin cut as shown in Fig. 1. When this metal is bent at
right angles on the dotted lines it will form a box as shown in
Fig. 2

[Illustration: Magic Lantern Details]

which is placed on a baseboard, 1/2 to 3/4 in. thick, 8 in. wide,
and 14 in. long. This box should be provided with a reflector
located just back of the lamp.

Procure a plano-convex or a bi-convex 6-in. lens with a focal
length of from 15 to 20 in. and a projecting lens 2 in. in
diameter with such a focal length that will give a picture of the
required size, or a lens of 12-in. focus enlarging a 3-in. slide
to about 6 ft. at a distance of 24 ft.

The woodwork of the lantern should be of 1/2-in., well seasoned
pine, white wood or walnut and the parts fastened together with
wood screws, wire brads, or glue, as desired. The board in which
to mount the condensing lens is 16 in. wide and 15 in. high,
battened on both ends to keep the wood from warping. The board is
centered both ways, and, at a point 1 in. above the center,
describe a 9-in. circle with a compass and saw the wood out with a
scroll or keyhole saw. If a small saw is used, and the work
carefully done, the circular piece removed will serve to make the
smaller portion of the ring for holding the condensing lens. This
ring is made up from two rings, A and B, Fig. 3. The inside and
outside diameters of the ring B are 3/8 in. greater than the
corresponding diameters of ring A, so when fastened together
concentrically an inner rabbet is formed for the reception of the
lens and an outer rabbet to fit against the board C in and against
which it rotates being held in place by buttons, DD.

A table, E, about 2 ft. long is fastened to the board C with
brackets F and supported at the outer end with a standard. The
slide support, G, and the lens slide, H, are constructed to slip
easily on the table, E, the strips II serving as guides. Small
strips of tin, JJ, are bent as shown and fastened at the top and
bottom of the rectangular opening cut in the support G for holding
the lantern slides.

All the parts should be joined together snugly and the movable
parts made to slide freely and when all is complete and well
sandpapered, apply two coats of shellac varnish. Place the lamp
house on the bottom board behind the condensing lens and the
lantern is ready for use.

The proper light and focus may be obtained by slipping the movable
parts on the board E, and when the right position is found for
each, all lantern slides will produce a clear picture on the
screen, if the position of the lantern and screen is not changed.
--Contributed by Stuart Mason Kerr, St. Paul, Minn.



** A Quickly Made Lamp [329]

A very simple lamp can be made from materials which are available
in practically every household in the following manner: A cheap
glass tumbler is partly filled with water and then about 1/2 in.
of safe, light burning oil, placed on the water. Cut a thin strip
from an ordinary cork and make a hole in the center to carry a
short piece of wick. The wick should

[Illustration: Lamp]

be of such a length as to dip into the oil, but not long enough.
To reach the water. The upper surface of the cork may be protected
from the flame with a small piece of tin bent over the edges and a
hole punched in the center for the wick. The weight of the tin
will force the cork down into the oil. The level of the oil should
be such as to make the flame below the top of the tumbler and the
light then will not be blown out with draughts. The arrangement is
quite safe as, should the glass happen to upset, the water at once
extinguishes the flame.
--Contributed by G. P. B.



** How to Make a Paper Aeroplane [329]

A very interesting and instructive toy aeroplane can be made as
shown in the accompanying illustrations. A sheet

[Illustration: Folding the Paper]

of paper is first folded, Fig. 1, then the corners on one end are
doubled over, Fig. 2, and the whole piece finished up and held
together with a paper clip as in Fig. 3. The paper clip to be used
should be like the one shown in Fig. 4. If one of these clips is
not at hand, form a piece of wire in the same shape, as it will be
needed for balancing purposes as well as for holding the paper
together. Grasp the aeroplane between the thumb and forefinger at
the place marked A in Fig. 3, keeping the paper as level as
possible and throwing it as you would a dart. The aeroplane will
make an easy and graceful flight in a room where no air will
strike it.
--Contributed by J.H. Crawford, Schenectady, N. Y.



** Bronze Liquid [329]

Banana oil or amyl acetate is a good bronze liquid.



** A Wrestling Mat [330]

The cost of a wrestling mat is so great that few small clubs can
afford to own one. As we did not see our way

[Illustration: Made of Bed Mattresses]

clear to purchase such a mat, I made one of six used bed
mattresses (Fig. 1) purchased from a second-hand dealer. I ordered
a canvas bag, 12 ft. 3 in. by 12 ft. 9 in., from a tent company,
to cover the mattresses. The bag consisted of two pieces with the
seam along each edge. The mattresses were laid side by side and
end to end and the bag placed on and laced up as shown in Fig. 2.
--Contributed by Walter W. White, Denver, Colo.



** A Pocket Voltammeter [330]

Remove the works and stem from a discarded dollar watch, drill two
3/16 in. holes in the edge, 3/4 in. apart, and insert two
binding-posts, Fig. 1, insulating them from the case with
cardboard. Fold two strips of light cardboard, 1/2 in. wide, so as
to form two oblong boxes, 1/2 in. long and 3/16 in. thick, open on
the edges. On one of these forms wind evenly the wire taken from a
bell magnet to the depth of 1/8 in. and on the other wind some 20
gauge wire to the same depth. Fasten the wire with gummed label,
to keep it from unwinding.

Glue the coils to the back of the case and connect one wire from
each binding-post as shown in Fig. 2, while the other two wires
are connected to an induction coil lead which is inserted in the
hole from which the stem was removed. Fasten a brass-headed tack
to the case at the point F with sealing wax or solder and bend a
wire in the shape shown in Fig. 3 to swing freely on the tack.
Attach a piece of steel rod, 3/4 in. long, in the center coil, C,
Fig. 2.

A rubber band, D, connects the steel rod C with the top of the
watch case. The ends of the rubber are fastened with sealing wax.
The rubber keeps the pointer at zero or in the middle of the
scale. Do not use too strong a rubber. A dial may be made by
cutting a piece of stiff white paper so it will fit under the
crystal of the watch. An arc is cut in the paper, as shown in Fig.
1, through which the indicator works.

To calibrate the instrument, first mark the binding-post A, which
is connected to the coil of heavy wire, for amperes and the other
post, V, to the coil of small wire for volts. Connect the lead and
the post marked A to one, two and three cells and each time mark
the place of the pointer on the dial. Take corresponding readings
on a standard ammeter and mark the figures on the dial. The volt
side of the dial may be calibrated in the same manner, using a
voltmeter instead of the ammeter. The place where the

[Illustration: Voltammeter in a Watch Case]

indicator comes to rest after disconnecting the current is marked
zero.
--Contributed by Edward M. Teasdale, Warren, Pa.



** A Film Washing Trough [331]

[Illustration: Washing a Negative Film]

The washing of films without scratching them after they are
developed and fixed is very difficult in hot weather. A convenient
washing trough for washing full length films is shown in the
accompanying sketch. The trough must be made for the size of the
film to be washed. Cut a 1/4-in. board as long as the film and a
trifle wider than the film's width. Attach strips to the edges of
the board to keep the water from spilling over the sides.

Cut a hole in one side of a baking powder can about half way
between the top and bottom, large enough to admit a fair-sized
stream of water from a faucet. Then solder the cover to the can
and punch a number of holes about 1/4 in. apart along the opposite
side from where the large hole was cut. Place this can on one end
of the trough, as shown, with the large hole up.

Some heavy wire bent in the shape of a U and fastened to the under
side of the trough at the can end will furnish supports to keep
that end of the trough the highest and place the opening in the
can close beneath the water faucet. A common pin stuck through one
end of the film and then in the trough close to the can will hold
it in position for washing. Five minutes' washing with this device
is sufficient to remove all traces of the hypo from the film.
--Contributed by M. M. Hunting, Dayton, O.



** Wood Burning [331]

[Illustration: Burnt Wood]

Burnt wood work done with an ordinary reading glass and the sun's
rays.



** The Diving Bottle [331]

This is a very interesting and easily performed experiment
illustrating the transmission of pressure by liquids. Take a
wide-mouthed bottle and fill almost full of water; then into this
bottle place, mouth downward, a small vial or bottle having just
enough air in the bottle to keep it barely afloat. Put a sheet of
rubber over the mouth of the large bottle, draw the edge down over
the neck and wrap securely with a piece of string thus forming a
tightly stretched diaphragm over the top. When a finger is pressed
on the rubber the small bottle will slowly descend until the
pressure is released when the

[Illustration: Pressure Experiments]

small bottle wilt ascend. The moving of the small bottle is caused
by the pressure transmitted through the water, thus causing the
volume of air in the small tube to decrease and the bottle to
descend and ascend when released as the air increases to the
original volume.

This experiment can be performed with a narrow-necked bottle,
provided the bottle is wide, but not very thick. Place the small
bottle in as before, taking care not to have too much air in the
bottom. If the cork is adjusted properly, the bottle may be held
in the hand and the sides pressed with the fingers, thus causing
the small bottle to descend and ascend at will. If the small
bottle used is opaque, or an opaque tube such as the cap of a
fountain pen, many puzzling effects may be obtained. --Contributed
by John Shahan, Auburn, Ala.



** How to Make an Inexpensive Wooden Fan [332]

Select a nice straight-grained piece of white pine about 1/4 in.
thick, 3/4 in. wide and 4 in. long. Lay out the design desired and
cut as shown in Fig. 1, and then soak the wood in hot water to
make it soft and easy to split. Cut the divisions very thin with a
sharp knife down to the point A, as shown in the sketch, taking
care not to split the wood through the part left for the handle.
The fan is then finished by placing each piece over the other as
in Fig. 2. This will make a very pretty ornament.
--Contributed by Fred W. Whitehouse, Upper Troy, N.Y.

[Illustration: Cutting the Wood and Complete Fan]



** Combination Telegraph and Telephone Line [332]

The accompanying diagrams show connections for a short line system

[Illustration: Wiring Diagram]

(metallic circuit) of telegraph where a telephone may be used in
combination on the line. The telephone receivers can be used both
as receivers and transmitters, or ordinary telephone transmitters,
induction coils and battery may be used in the circuit with a
receiver. If a transmitter is used, its batteries may be connected
in circuit with a common push button which is held down when using
the telephone. On a 1000-ft. line, four dry cells will be
sufficient for the telegraph instruments and two cells for the
telephone.
--Contributed by D. W. Milter.



** How to Make a Miniature Windmill [333]

The following description is how a miniature windmill was made,
which gave considerable power for its size, even in a light
breeze. Its smaller parts, such as blades and pulleys, were
constructed of 1-in. sugar pine on account of its softness.

The eight blades were made from pieces 1 by 1-1/2 by 12 in. Two
opposite edges were cut away until the blade was about 1/8 in.
thick. Two inches

[Illustration: Details of Miniature Windmill Construction]

were left uncut at the hub end. They were then nailed to the
circular face plate A, Fig. 1, which was 6 in. in diameter and 1
in. thick. The center of the hub was lengthened by the wooden
disk, B, Fig. 1, which was nailed to the face plate. The shaft C,
Fig. 1, was 1/4-in. iron rod, 2 ft. long, and turned in the
bearings detailed in Fig. 2. J was a nut from a wagon bolt and was
placed in the bearing to insure easy running. The bearing blocks
were 3 in. wide, 1 in. thick and 3 in. high without the upper
half. Both bearings were made in this manner.

The shaft C was keyed to the hub of the wheel, by the method shown
in Fig. 3. A staple, K, held the shaft from revolving in the hub.
This method was also applied in keying the 5-in. pulley F, to the
shaft, G, Fig. 1, which extended to the ground. The 2-1/2-in.
pulley, I, Fig. 1, was keyed to shaft C, as shown in Fig. 4. The
wire L was put through the hole in the axle and the two ends
curved so as to pass through the two holes in the pulley, after
which they were given a final bend to keep the pulley in place.
The method by which the shaft C was kept from working forward is
shown in Fig. 5. The washer M intervened between the bearing block
and the wire N, which was passed through the axle and then bent to
prevent its falling out. Two washers were placed on shaft C,
between the forward bearing and the hub of the wheel to lessen the
friction.

The bed plate D, Fig. 1, was 2 ft. long, 3 in. wide and 1 in.
thick and was tapered from the rear bearing to the slot in which
the fan E was nailed. This fan was made of 1/4-in. pine 18 by 12
in. and was cut the shape shown. The two small iron pulleys with
screw bases, H, Fig. 1, were obtained for a small sum from a
hardware dealer. Their diameter was 1-1/4 in. The belt which
transferred the power from shaft C to shaft G was top string, with
a section of rubber in it to take up slack. To prevent it from
slipping on the two wooden pulleys a rubber band was placed in the
grooves of each.

The point for the swivel bearing was determined by balancing the
bed plate, with all parts in place, across the thin edge of a
board. There a 1/4-in. hole was bored in which shaft G turned. To
lessen the friction here, washers were placed under pulley F. The
swivel bearing was made from two lids of baking powder cans. A
section was cut out of one to permit its being enlarged enough to
admit the other. The smaller one, 0, Fig. 6, was nailed top down
with the sharp edge to the underside of the bed plate, so that the
1/4-in. hole for the shaft G was in the center. The other lid, G,
was tacked, top down also, in the center of the board P, with
brass headed furniture tacks, R, Fig. 6, which acted as a smooth
surface for the other tin to revolve upon. Holes for shaft G were
cut through both lids. Shaft G was but 1/4 in. in diameter, but to
keep it from rubbing against the board P, a 1/2-in. hole was bored
for it, through the latter.

The tower was made of four 1 by 1 in. strips, 25 ft. long. They
converged from points on the ground forming an 8-ft. square to the
board P at the top of the tower. This board was 12 in. square and
the corners were notched to admit the strips as shown, Fig. 1.
Laths were nailed diagonally between the strips to strengthen the
tower laterally. Each strip was screwed to a stake in the ground
so that by disconnecting two of them the other two could be used
as hinges and the tower could be tipped over and lowered to the
ground, as, for instance, when the windmill needed oiling.
Bearings for the shaft G were placed 5 ft. apart in the tower. The
power was put to various uses.



** How to Make a Telegraph Instrument and Buzzer [334]

The only expenditure necessary in constructing this telegraph
instrument is the price of a dry cell, providing one has a few old
materials on hand. Procure a block of wood about 6 in. long and 3
in. wide and take the coils out of an old electric bell. If you
have no bell, one may be had at the dealers for a small sum.
Fasten these coils on the blocks at one end as in Fig. 1. Cut a
piece of tin 2 in. long and 1/2 in. wide and bend it so the end of
the tin

[Illustration: Home-Made Telegraph Instrurment]

when fastened to the block will come just above the core of the
coil. Cut another piece of tin 3 in. long and bend it as shown at
A, Fig. 2. Tack these two pieces of tin in front of the coils as
shown in the illustration. This completes the receiver or sounder.

To make the key, cut out another piece of tin (X, Fig. 1) 4 in.
long and bend it as shown. Before tacking it to the board, cut off
the head of a nail and drive it in the board at a point where the
loose end of the tin will cover it. Then tack the key to the board
and connect the wires of the battery as in Fig. 1. Now, move the
coils back and forth until the click sounds just the way you wish
and you are ready to begin on the Morse code.

When tired of this instrument, connect the wire from the coils to
the key to point A and the one connected at the point under the
key to B, leaving the other wire as it is. By adjusting the coils,
the receiver will begin to vibrate rapidly, causing a buzzing
sound.
--Contributed by John R. McConnell.



** How to Make a Water Bicycle [335]

Water bicycles afford fine sport, and, like many another device
boys make, can be made of material often cast off by their people
as rubbish. The principle material necessary for the construction
of a water bicycle is oil barrels. Flour barrels will not do-they
are not strong enough, nor can they be made perfectly airtight.
The grocer can furnish you with oil barrels at a very small cost,
probably let you have them for making a few deliveries for him.
Three barrels are required for the water bicycle, although it can
be made with but two. Figure 1 shows the method of arranging the
barrels; after the manner of bicycle wheels.

Procure an old bicycle frame and make for it a board platform
about 3 ft. wide at the rear end and tapering to about 2 ft. at
the front, using cleats to hold the board frame, as shown at

[Illustration: Water, Bicycle Complete]

the shaded portion K. The construction of the barrel part is shown
in Fig. 2. Bore holes in the center of the heads of the two rear
barrels and also in the heads of the first barrel and put a shaft
of wood, through the rear barrels and one through the front
barrel, adjusting the side pieces to the shafts, as indicated.

Next place the platform of the bicycle frame and connections
thereon. Going back to Fig. 1 we see that the driving chain passes
from the sprocket driver L of the bicycle frame to the place
downward between the slits in the platform to the driven sprocket
on the shaft between the two barrels. Thus a center drive is made.
The rear barrels are, fitted with paddles as at M, consisting of
four pieces of board nailed

[Illustration: Barrel Float for Bicycle]

and deated about the circumference of the barrels, as shown in
Fig. 1.

The new craft is now ready for a first voyage. To propel it, seat
yourself on the bicycle seat, feet on the pedals, just as you
would were you on a bicycle out in the street. The steering is
effected by simply bending the body to the right or left, which
causes the craft to dip to the inclined side and the affair turns
in the dipped direction. The speed is slow at first, but increases
as the force is generated and as one becomes familiar with the
working of the affair. There is no danger, as the airtight barrels
cannot possibly sink.

Another mode of putting together the set of barrels, using one
large one in the rear and a small one in the front is presented in
Fig, 3. These two barrels are empty oil barrels like the others.
The head holes are bored and the proper wooden shafts are inserted
and the entrance to the bores closed tight by calking with hemp
and putty or clay. The ends of the shafts turn in the wooden frame
where the required bores are made to receive the same. If the
journals thus made are well oiled, there will not be much
friction. Such a frame can be fitted with a platform and a raft to
suit one's individual fancy built upon it, which can

[Illustration: Another Type of Float]

be paddled about with ease and safety on any pond. A sail can be
rigged up by using a mast and some sheeting; or even a little
houseboat, which will give any amount of pleasure, can be built.



** How To Make a Small Searchlight [336]

The materials required for a small searchlight are a 4-volt lamp
of the loop variety, thin sheet brass for the cylinder, copper
piping and brass tubing for base. When completed the searchlight
may be fitted to a small boat and will afford a great amount

[Illustration: Searchlight]

of pleasure for a little work, or it may be put to other uses if
desired.

Make a cylinder of wood of the required size and bend a sheet of
thin brass around it. Shape small blocks of boxwood, D, Fig. 1, to
fit the sides and pass stout pieces of brass wire through the
middle of the blocks for trunnions. Exactly through the middle of
the sides of the cylinder drill holes just so large that when the
blocks containing the trunnions are cemented to the cylinder there
is no chance of contact between cylinder and trunnion, and so
creating a false circuit.

The trunnion should project slightly into the cylinder, and after
the lamp has been placed in position by means of the small wood
blocks shown in Fig. 1, the wires from the lamp should be soldered
to the trunnions. It is best to solder the wire to the trunnions
before cementing the side blocks inside the cylinder.

Turn a small circle of wood, A, Fig. 2, inside the cylinder to fit
exactly and fasten to it a piece of mirror, C, Fig. 2, exactly the
same size to serve as a reflector. Painting the wood with white
enamel or a piece of brightly polished metal will serve the
purpose. On the back of the piece of wood fasten a small brass
handle, B, Fig. 2, so that it may readily be removed for cleaning.

In front of cylinder place a piece of magnifying glass for a lens.
If a piece

[Illustration: Front View;  Side View]

to fit cannot be obtained, fit a glass like a linen tester to a
small disc of wood or brass to fit the cylinder. If magnifying
glass cannot be had, use plain glass and fit them as follows:

Make two rings of brass wire to fit tightly into the cylinder,
trace a circle (inside diameter of cylinder) on a piece of
cardboard; place cardboard on glass and cut out glass with a glass
cutter; break off odd corners with notches on cutters and grind
the edge of the glass on an ordinary red brick using plenty of
water. Place one brass ring in cylinder, then the glass disc and
then the other ring.

For the stand fill a piece of copper piping with melted rosin or
lead. When hard bend the pipe around a piece of wood which has
been sawed to the shape of bend desired. Then melt out the rosin
or lead. Make an incision with a half-round file in the under side
of the tube for the wires to come through. Make the base of wood
as shown in Fig. 1. One half inch from the top bore a hole large
enough to admit the copper pipe and a larger hole up the center to
meet it for the wires to come down.

If it is desired to make the light very complete, make the base of
two pieces of brass tube--one being a sliding fit in the other and
with projecting pieces to prevent the cylinder from going too far.
The light may then be elevated or lowered as wished. On two
ordinary brass terminals twist or solder some flexible wire, but
before doing so fix a little bone washer on the screws of the
terminal so as to insulate it from the tube. When the wires have
been secured to the terminals cover the joint with a piece of very
thin india rubber tubing, such as is used for cycle valves. The
two wires may now be threaded down the copper tube into the base,
and pulled tight, the terminals firmly fixed into the tubes; if
too small, some glue will secure them. To get the cylinder into
its carriage, put one trunnion into the terminal as far as it will
go and this will allow room for the other trunnion to go in its
terminal.



** Electric Alarm that Rings a Bell and Turns on a Light [337]

The illustration shows an alarm clock connected up to ring an
electric bell, and at the same time turn on an electric light to
show the time. The parts indicated are as follows: A, key of alarm
clock; B, contact post, 4 in. long; C, shelf, 5-1/4 by 10 in.; D,
bracket; E, electric bulb (3-1/2 volts) ; S, brass strip, 4-1/2
in. long, 3/8 in. wide and 1/16 in. thick; T, switch; F, wire from
batteries to switch; G, wire from bell to switch; H, wire from
light to switch; I, dry batteries; J, bell; X, point where a
splice is made from the light to wire leading to batteries from
brass strip under clock. Push the switch lever to the right before
retiring.

To operate this, set alarm key as shown in diagram, after two
turns have been made on the key. When alarm goes off, it turns
till it forms a connection by striking the contact post and starts
the electric bell ringing. Throw lever off from the right to
center, which stops bell ringing. To throw on light throw levers
to the left. The bell is then cut out but the light remains on
till lever is again thrown in the center,

[Illustration: Details of Alarm Construction]

In placing clock on shelf, after setting alarm, be sure that the
legs of clock are on the brass strip and that the alarm key is in
position so it will come in contact with the contact post in back
of clock. The contact post may be of 1/4-in. copper tubing, or
1/4-in. brass rod.

The advantage of this is that one can control the bell and light,
while lying in bed, by having the switch on the baseboard, near
the bed, so it can be reached without getting out of bed.
--Contributed by Geo. C. Brinkerhoff, Swissvale, Pa.



** How to Hold a Screw on a Screwdriver [337]

A screw that is taken from a place almost inaccessible with the
fingers requires considerable patience to return it with an
ordinary screwdriver unless some holding-on device is used. I have
found that by putting a piece of cardboard or thick paper with the
blade of the screwdriver in the screw head slot, the screw may be
held and turned into places that it would be impossible with the
screwdriver alone.
--Contributed by C. Chatland, Ogden, Utah.



** How to Make a Lead Cannon [338]

Any boy who has a little mechanical ability can make a very
reliable cannon for his Fourth-of-July celebration by following
the instructions given here:

[Illustration: Lead Cannon Construction]

Take a stick--a piece of curtain roller will do--7 in. long. Make
a shoulder, as at A, Fig. 1, 4 in. from one end, making it as true
and smooth as possible, as this is to be the muzzle of the cannon.
Make the spindle as in Fig. 1, 1/4 in. in diameter. Procure a good
quality of stiff paper, about 6 in. wide, and wrap it around the
shoulder of the stick, letting it extend 3/4 in. beyond the end of
the spindle, as at B, Fig. 2. Push an ordinary shingle nail
through the paper and into the extreme end of the spindle, as at
A, Fig. 2. This is to form the fuse hole.

Having finished this, place stick and all in a pail of sand, being
careful not to get the sand in it, and letting the opening at the
top extend a little above the surface of the sand. Then fill the
paper cylinder with melted lead and let cool. Pull out the nail
and stick, scrape off the paper and the cannon is ready for
mounting, as in Fig. 3.
--Contributed by Chas. S. Chapman, Lanesboro, Minn.



** Homemade Electric Bed Warmer [338]

The heat developed by a carbon-filament lamp is sufficiently high
to allow its use as a heating element of, for instance, a bed
warmer. There are a number of other small heaters which can be
easily made and for which lamps form very suitable heating
elements, but the bed warmer is probably the best example. All
that is required is a tin covering, which can be made of an old
can, about 3-1/2 in. in diameter. The top is cut out and the edge
filed smooth. The lamp-socket end of the flexible cord is inserted
in the can and the shade holder gripped over the opening. A small
lamp of about 5 cp. will do the heating.

A flannel bag, large enough to slip over the tin can and provided
with a neck that can be drawn together by means of a cord, gives
the heater a more finished appearance, as well as making it more
pleasant to the touch.



** Making a Fire with the Aid of Ice [338]

Take a piece of very clear ice and melt it down into the hollow of
your hands so as to form a large lens. The illustration shows how
this is done. With the lens-shaped ice used in the same manner as
a reading glass to

[Illustration: Forming the Ice Lens]

direct the sun's rays on paper or shavings you can start a fire.
--Contributed by Arthur E. Joerin.



** How to Make a Crossbow and Arrow Sling [339]

In making of this crossbow it is best to use maple for the stock,
but if this wood cannot be procured, good straight-grained pine
will do. The

[Illustration: Details of the Bow-Gun and Arrow Sling]

material must be 1-1/2 in. thick, 6 in. wide and a trifle over 3
ft. long. The bow is made from straight-grained oak, ash, or
hickory, 5/8 in. thick, 1 in. wide and 3 ft. long. A piece of oak,
3/8 in. thick, 1-1/2 in. wide and 6 ft. long, will be sufficient
to make the trigger, spring and arrows. A piece of tin, some nails
and a good cord will complete the materials necessary to make the
crossbow.

The piece of maple or pine selected for the stock must be planed
and sandpapered on both sides, and then marked and cut as shown in
Fig. 1. A groove is cut for the arrows in the top straight edge
3/8 in. wide and 3/8 in. deep. The tin is bent and fastened on the
wood at the back end of the groove where the cord slips out of the
notch; this is to keep the edges from splitting.

A mortise is cut for the bow at a point 9-1/2 in. from the end of
the stock, and one for the trigger 12 in. from the opposite end,
which should be slanting a little as shown by the dotted lines. A
spring, Fig. 2, is made from a good piece of oak and fastened to
the stock with two screws. The trigger, Fig. 3, which is 1/4 in.
thick, is inserted in the mortise in the position when pulled
back, and adjusted so as to raise the spring to the proper height,
and then a pin is put through both stock and trigger, having the
latter swing quite freely. When the trigger is pulled, it lifts
the spring up, which in turn lifts the cord off the tin notch.

The stick for the bow, Fig. 4, is dressed down from a point 3/4
in. on each side of the center line to 1/2 in. wide at each end.
Notches are cut in the ends for the cord. The bow is not fastened
in the stock, it is wrapped with a piece of canvas 1-1/2 in. wide
on the center line to make a tight fit in the mortise. A stout
cord is now tied in the notches cut in the ends of the bow making
the cord taut when the wood is straight.

The design of the arrows is shown in Fig. 5 and they are made with
the blades much thinner than the round part.

To shoot the crossbow, pull the cord back and down in the notch as
shown in Fig. 6, place the arrow in the groove, sight and pull the
trigger as in shooting an ordinary gun.

The arrow sling is made from a branch of ash about 1/2 in. in
diameter, the bark removed and a notch cut in one end, as shown in
Fig. 7. A stout cord about 2-1/2 ft. long is tied in the notch and
a large knot made in the other or loose end. The arrows are
practically the same as those used on the crossbow, with the
exception of a small notch which is cut in them as shown in Fig.
8.

To throw the arrow, insert the cord near the knot in the notch of
the arrow, then grasping the stick with the right hand and holding
the wing of the arrow with the left, as shown in Fig. 9, throw the
arrow with a quick slinging motion. The arrow may be thrown
several hundred feet after a little practice.
--Contributed by O. E. Trownes, Wilmette, Ill.



** A Home-Made Vise [340]

Cut two pieces of wood in the shape shown in the sketch and bore a
3/8-in. hole through both of them for a common carriage bolt.
Fasten one of the pieces to the edge of the bench with a large
wood screw and attach the other piece to the first one with a
piece of leather nailed across the bottom of both pieces. The nut
on the carriage bolt may be tightened with a wrench,

[Illustration: Details of a Home-Made Bench Vise]

or, better still, a key filed out of a piece of soft steel to fit
the nut. The edges of the jaws are faced with sheet metal which
can be copper or steel suitable for the work it is intended to
hold.



** Temporary Dark Room Lantern [340]

Occasionally through some accident to the regular ruby lamp, or
through the necessity of, developing while out of reach of a
properly equipped dark room, some makeshift of illumination must
be improvised. Such a temporary safe light may be made from an
empty cigar box in a short time.

[Illustration: Lantern]

Remove the bottom of the box, and nail it in position as shown at
A. Remove one end, and replace as shown at B. Drive a short wire
nail through the center of the opposite end to serve as a seat for
the candle, C. The lamp is finished by tacking two or more layers
of yellow post-office paper over the aperture D, bringing the
paper well around to the sides and bottom of the box to prevent
light leakage from the cracks around the edges, says Photo Era.
The hinged cover E, is used as a door, making lighting and
trimming convenient. The door may be fastened with a nail or piece
of wire. It is well to reinforce the hinge by gluing on a strip of
cloth if the lamp is to be in use more than once or twice. This
lamp is safe, for the projecting edges of A and B form
light-shields for the ventilation orifice and the crack at the top
of the hinged cover, respectively. Moreover, since the flame of
the candle is above A, only reflected and transmitted light
reaches the plate, while the danger of igniting the paper is
reduced to a minimum.



** Runny Paint [340]

The paint will sag and run if too much oil is put in white lead.



** Camps and How to Build Them [341]

There are several ways of building a temporary camp from material
that is always to be found in the woods, and whether these
improvised shelters are intended to last until a permanent camp is
built, or only as a camp on a short excursion, a great deal of fun
can be had in their construction. The Indian camp is the easiest
to make. An evergreen tree with branches growing well down toward
the ground furnishes all the material. By chopping the trunk
almost through, so that when the tree falls the upper part will
still remain attached to the stump, a serviceable shelter can be
quickly provided. The cut should be about 5 ft. from the ground.
Then the boughs and branches on the under side of the fallen top
are chopped away and piled on top. There is room for several
persons under this sort of shelter, which offers fairly good
protection against any but the most drenching rains.

The Indian wigwam sheds rain better, and where there are no
suitable trees that can be cut, it is the easiest camp to make.
Three long poles with the tops tied together and the lower ends
spaced 8 or 10 ft. apart, make the frame of the wigwam. Branches
and brush can easily be piled up, and woven in and out on these
poles so as to shed a very heavy rain.

The brush camp is shaped like an ordinary "A" tent. The ridge pole
should be about 8 ft. long and supported by crotched uprights
about 6 ft. from the ground. Often the ridge pole can be laid from
one small tree to another. Avoid tall trees on account of
lightning. Eight or ten long poles are then laid slanting against
the ridge pole on each side. Cedar or hemlock boughs make the best
thatch for the brush camp. They should be piled up to a thickness
of a foot or more over the slanting poles and woven in and out to
keep them from slipping. Then a number of poles should be laid
over them to prevent them from blowing away. In woods where there
is plenty of bark available in large slabs, the bark lean-to is a
quickly constructed and serviceable camp. The ridge pole is set up
like that of the brush camp. Three or four other poles are laid
slanting to the ground on one side only. The ends of these poles
should be pushed into the earth and fastened with crotched sticks.
Long poles are then laid crossways of these slanting poles, and
the whole can be covered with brush as in the case of the brush
camp or with strips of bark laid overlapping each other like
shingles. Where bark is used, nails are necessary to hold it in
place. Bark may also be used for a wigwam and it can be held in
place by a cord wrapped tightly around the whole structure,
running spiral-wise from the ground to the peak. In the early
summer, the bark can easily be removed from most trees by making
two circular cuts around the trunk and joining them with another
vertical cut. The bark is easily pried off with an ax, and if laid
on the ground under heavy stones, will dry flat. Sheets of bark, 6
ft. long and 2 or 3 ft. wide, are a convenient size for camp
construction.

The small boughs and twigs of hemlock, spruce, and cedar, piled 2
or 3 ft. deep and covered with blankets, make the best kind of a
camp bed. For a permanent camp, a bunk can be made by laying small
poles close together across two larger poles on a rude framework
easily constructed. Evergreen twigs or dried leaves are piled on
this, and a blanket or a piece of canvas stretched across and
fastened down to the poles at the sides. A bed like this is soft
and springy and will last through an ordinary camping season
without renewal. A portable cot that does not take up much room in
the camp outfit is made of a piece of heavy canvas 40 in. wide and
6 ft. long. Four-inch hems are sewed in each side of the canvas,
and when the camp is pitched, a 2-in. pole is run through each hem
and the ends of the pole supported on crotched sticks.

[Illustration: Camp Details]

Fresh water close at hand and shade for the middle of the day are
two points that should always be looked for in. selecting a site
for a camp. If the camp is to be occupied for any length of time,
useful implements for many purposes can be made out of such
material as the woods afford. The simplest way to build a crane
for hanging kettles over the campfire is to drive two posts into
the ground, each of them a foot or more from one end of the fire
space, and split the tops with an ax, so that a pole laid from one
to the other across the fire will be securely held in the split.
Tongs are very useful in camp. A piece of elm or hickory, 3 ft.
long and 1-1/2 in. thick, makes a good pair of tongs. For a foot
in the middle of the stick, cut half of the thickness away and
hold this part over the fire until it can be bent easily to bring
the two ends together, then fasten a crosspiece to hold the ends
close together, shape the ends so that anything that drops into
the fire can be seized by them, and a serviceable pair of tongs is
the result. Any sort of a stick that is easily handled will serve
as a poker. Hemlock twigs tied around one end of a stick make an
excellent broom. Movable seats for a permanent camp are easily
made by splitting a log, boring holes in the rounded side of the
slab and driving pegs into them to serve as legs. A short slab or
plank can easily be made into a three-legged stool in the same
way.

Campers usually have boxes in which their provisions have been
carried. Such a packing box is easily made into a cupboard, and it
is not difficult to improvise shelves, hinges, or even a rough
lock for the camp larder.

A good way to make a camp table is to set four posts into the
ground and nail crosspieces to support slabs cut from chopped wood
logs to form a top. Pieces can be nailed onto the legs of the
table to hold other slabs to serve as seats, and affording
accommodation for several persons.



** Brooder for Small Chicks [343]

A very simple brooder can be constructed by cutting a sugar barrel
in half and using one part in the manner

[Illustration: Brooder for Young Chicks Kept Warm with a Jug of
Boiling Water]

described. Line the inside of the half  barrel with paper and then
cover this with old flannel cloth. Make a cover for the top and
line it in the same manner. At the bottom cut a hole in the edge,
about 4 in. deep and 4 in. wide, and provide a cover or door. The
inside is kept warm by filling a jug with boiling water and
setting it within, changing the water both morning and night. When
the temperature outside is 10 deg. the interior can, be kept at 90
or 100 deg., but the jug must be refilled with boiling water at
least twice a day.



** Faucet Used as an Emergency Plug [343]

A brass faucet split as shown at A during a cold spell, and as no
suitable plug to screw into the elbow after removing the faucet
was at hand, I drove a small cork, B, into the end of the faucet
and screwed it back in place. The cork converted the faucet into
an

[Illustration: A Tight-Fitting Cork Driven into a Cracked Faucet
Converted It into an Emergency Plug]

emergency plug which prevented leakage until the proper fitting to
take its place could be secured.
--Contributed by James M. Kane, Doylestown, Pa.



** Automatic Electric Heat Regulator [344]

It is composed of a closed glass tube, A, Fig. 1, connected by
means of a very small lead pipe, B, to another

[Illustration: Heat Regulator]

glass tube, C, open at the bottom and having five pieces of
platinum wire (1, 2, 3, 4 and 5), which project inside and outside
of the tube, fused into one side. This tube is plunged into an
ebonite vessel of somewhat larger diameter, which is fastened to
the base by a copper screw, E. The tube C is filled to a certain
height with mercury and then petroleum. The outer ends of the five
platinum wires are soldered to ordinary copper wires and
connections made to various points on a rheostat as shown. The
diagram, Fig. 2, shows how the connections to the supply current
are made. The apparatus operates as follows: The tube is immersed
in the matter to be heated, a liquid, for instance. As

[Illustration: Wiring Diagram Showing How the Connections to a
Source of Current Supply are Made]

the temperature of this rises, the air expands and exerts pressure
on the petroleum in the tube C so that the level of the mercury is
lowered. The current is thus compelled, as the platinum wires with
the fall of the mercury are brought out of circuit, to pass
through an increasing resistance, until, if necessary, the flow is
entirely stopped when the mercury falls below the wire 5.

With this very simple apparatus the temperature can be kept
constant within a 10-deg. limit, and it can be made much more
sensitive by increasing the number of platinum wires and placing
them closer together, and by filling the tube A with some very
volatile substance, such as ether, for instance. The petroleum
above the mercury prevents sparking between the platinum wire and
the mercury when the latter falls below anyone of them.



** Repairing a Washer on a Flush Valve [344]

When the rubber washer on the copper flush valve of a soil-basin
tank becomes loose it can be set by pouring a small quantity of
paraffin between the rubber and the copper while the valve is
inverted, care being taken to have the rubber ring centered. This
makes

[Illustration: Flush Valve]

a repair that will not allow a drop ot water to leak out of the
tank.
--Contributed by Frank Jermin, Alpena, Michigan.



** Cleaning Discolored Silver [344]

A very quick way to clean silver when it is not tarnished, but
merely discolored, is to wash the articles in a weak solution of
ammonia water. This removes the black stains caused by sulphur in
the air. After cleaning them with the solution, they should be
washed and polished in magnesia powder or with a cloth. This
method works well on silver spoons tarnished by eggs and can be
used every day while other methods require much time and,
therefore, cannot be used so often.



** How to Make a Small Electric Motor [345]
By W. A. ROBERTSON

The field frame of the motor, Fig. 1, is composed of wrought sheet
iron, which may be of any thickness so that, when several pieces
are placed together, they will make a frame 3/4 in. thick. It is
necessary to layout a template of the frame as shown, making it
1/16 in. larger than the dimensions given, to allow for filing to
shape after the parts are fastened together. After the template is
marked out, drill the four rivet holes, clamp the template, or
pattern, to the sheet iron and mark carefully with a scriber. The
bore can be marked with a pair of dividers, set at 1/8 in. This
will mark a line for the center of the holes to be drilled with a
1/4-in. drill for removing the unnecessary metal. The points
formed by drilling the holes can be filed to the pattern size. Be
sure to mark and cut out a sufficient number of plates to make a
frame 3/4 in. thick, or even 1/16 in. thicker, to allow for
finishing.

After the plates are cut out and the rivet holes drilled, assemble
and rivet them solidly, then bore it out to a diameter of 2-3/4
in. on a lathe. If the thickness is sufficient, a slight finishing
cut can be taken on the face. Before removing the field from the
lathe, mark off a space, 3-3/8 in. in diameter, for the field core
with a sharp-pointed tool, and for the outside of the frame, 4-1/2
in. in diameter, by turning the lathe with the hand. Then the
field can be finished to these marks, which will make it uniform
in size. When the frame is finished so far, two holes, 3-3/8 in.
between centers, are drilled and tapped with a 3/8-in. tap. These
holes are for the bearing studs. Two holes are also drilled and
tapped for 1/4-in. screws, which fasten the holding-down lugs or
feet to the frame. These lugs are made of a piece of 1/8-in. brass
or iron, bent at right angles as shown.

The bearing studs are now made, as shown in Fig. 2, and turned
into the threaded holes in the frame. The bearing supports are
made of two pieces of 1/8-in. brass, as shown in the left-hand
sketch, Fig. 3, which are fitted on the studs in the frame. A
5/8-in. hole is

[Illustration: The Field-Coil Core is Built Up of Laminated
Wrought Iron Riveted Together]

drilled in the center of each of these supports, into which a
piece of 5/8-in. brass rod is inserted, soldered into place, and
drilled to receive the armature shaft. These bearings should be
fitted and soldered in place after the armature is constructed.
The manner of doing this is to wrap a piece of paper on the
outside of the finished armature ring and place it through the
opening in the field, then slip the bearings on the ends of the
shaft. If the holes in the bearing support should be out of line,
file them out to make the proper adjustment. When the bearings are
located, solder them to the supports, and build up the solder
well. Remove

[Illustration: The Bearing Studs are Turned from Machine Steel Two
of Each Length being Required]

the paper from the armature ring and see that the armature
revolves freely in the bearings without touching the inside of the
field at any point. The supports are then removed and the solder
turned up in a lathe, or otherwise finished. The shaft of the
armature, Fig. 4, is turned up from machine steel, leaving the
finish of the bearings until the armature is completed and
fastened to the shaft.

The armature core is made up as

[Illustration: The Assembled Bearing Frame on the Field Core and
the Armature Shaft Made of Machine Steel]

follows: Two pieces of wrought sheet iron, 1/8 in. thick, are cut
out a little larger than called for by the dimensions given in
Fig. 5, to allow for finishing to size. These are used for the
outside plates and enough pieces of No. 24 gauge sheet iron to
fill up the part between until the whole is over 3/4 in. thick are
cut like the pattern. After the pieces are cut out, clamp them
together and drill six 1/8-in. holes through them for rivets.
Rivet them together, and anneal the whole piece by placing it in a
fire and heating the metal to a cherry red, then allowing it to
cool in the ashes. When annealed, bore out the inside to 1-11/16
in. in diameter and fit in a brass spider, which is made as
follows: Procure a piece of brass, 3/4 in. thick, and turn it up
to the size shown and file out the metal between the arms. Slip
the spider on the armature shaft and secure it solidly with the
setscrew so that the shaft will not turn in the spider when truing
up the armature core. File grooves or slots in the armature ring
so that it will fit on the arms of the spider. Be sure to have the
inside of the armature core run true. When this is accomplished,
solder the arms of the spider to the metal of the armature core.
The shaft with the core is then put in a lathe and the outside
turned off to the proper size. The sides are also faced off and
finished. Make the core 3/4 in. thick. Remove the core from the
lathe and file out slots 1/4 in. deep and 7/16 in. wide.

The commutator is turned from a piece of brass pipe, 3/4 in.
inside diameter, as shown in Fig. 6; The piece is placed on a
mandrel and turned to 3/4 in. in length and both ends chamfered to
an angle of 60 deg. Divide the surface into 12 equal parts, or
segments. Find the centers of each segment at one end, then drill
a 1/8-in. hole and tap it for a pin. The pins are made of brass,
threaded, turned into place and the ends turned in a lathe to an
outside diameter of 1-1/4 in. Make a slit with a small saw blade
in the end of each pin for the ends of the wires coming from the
commutator coils. Saw the ring into the 12 parts on the lines
between the pins.

The two insulating ends for holding these segments are made of
fiber turned to fit the bore of the brass tubing, as shown in Fig.
7. Procure 12 strips of mica, the same thickness as the width of
the saw cut made between the segments, and use them as a filler
and insulation between the commutator

[Illustration: Armature-Ring Core, Its Hub and the Construction of
the Commutator and Its Insulation]

bars. Place them on the fiber hub and slip the hub on the shaft,
then clamp the whole in place with the nut, as shown in Fig. 3.
True up the commutator in a lathe to the size given in Fig. 6.

The brush holder is shaped from apiece of fiber, as shown in Fig.
8. The studs for holding the brushes are cut from 5/16-in. brass
rod, as shown in Fig. 9. The brushes consist of brass or copper
wire gauze, rolled up and flattened out to 1/8 in. thick and 1/4
in. wide, one end being soldered to keep the wires in place. The
holder is slipped on the projecting outside end of the bearing, as
shown m Fig. 3, and held with a setscrew.

The field core is insulated before winding with 1/64-in. sheet
fiber, washers, 1-1/8 in. by 1-1/2 in., being formed for the ends,
with a hole cut in them to fit over the insulation placed on the
cores. A slit is cut through from the hole to the outside, and
then they are soaked in warm water, until they become flexible
enough to be put in place. After they have dried, they are glued
to the core insulation.

The field is wound with No. 18 gauge double-cotton-covered magnet
wire, about 100 ft. being required. Drill a small hole through
each of the lower end insulating washers. In starting to wind,
insert the end of the wire through the hole from the inside at A
Fig. 1, and wind on four layers, which will take 50 ft. of the
wire, and bring the end of the wire out at B. After one coil, or
side, is wound start at C in the same manner as at A, using the
same number of turns and the same length of wire. The two ends are
joined at B.

The armature ring is insulated by covering the inside and brass
spider with 1/16-in. sheet fiber. Two rings of 1/16-in sheet fiber
are cut and glued to the sides of the ring. When the glue is set,
cut out the part within the slot ends and make 12 channel pieces
from 1/64-in. sheet fiber, which are glued in the slots and to the
fiber washers. Be sure to have the ring and spider covered so the
wire will not touch the iron or brass.

Each slot of the armature is wound with about 12 ft. of No. 21
gauge double-cotton-covered magnet wire. The winding is started at
A, Fig. 5, by bending the end around one of the projections, then
wind the coil in one of the slots as shown, making 40 turns or
four layers of 10 turns each shellacking each layer as it is
wound. After the coil is completed in one slot allow about 2 in.
of the end to protrude, to

[Illustration: The Insulated Brush Holder and Its Studs for
Holding the Brushes on the Commutator]

fasten to the commutator segment. Wind the next slot with the same
number of turns in the same manner and so on, until the 12 slots
are filled. The protruding ends of the coils are connected to the
pins in the commutator segments after the starting end of one
coils is joined to the finishing end of the next adjacent. All
connections should be securely soldered.

The whole motor is fastened with screws to a wood base, 8 in.
long, 6 in. wide and 1 in. thick. Two terminals are fastened at
one side on the base and a switch at the other side.

To connect the wires, after the motor is on the stand, the two
ends of the wire, shown at B, Fig. 1, are soldered together. Run
one end of the field wire, shown at A, through a small hole in the
base and make a groove on the under side so that the wire end can
be connected to one of the terminals The other end of the field
wire C is connected to the brass screw in the brass brush stud.
Connect a wire from the other brush stud, run it through a small
hole in the base and cut a groove for it on the under side so that
it can be connected through the switch and the other terminal.
This winding is for a series motor. The source of current is
connected to the terminals. The motor can be run on a 110-volt
direct current, but a resistance must be placed in series with it.



** Protecting Tinware [347]

New tinware rubbed over with fresh lard and heated will never
rust.



** Another Optical Illusion [348]

After taking a look at the accompanying illustration you will be
positive that the cords shown run in a spiral toward the center,
yet it shows a series of

[Illustration: The Cord Is Not a Spiral]

perfect circles of cords placed one inside the other. You can test
this for yourself in a moment with a pair of compasses, or, still
more simply, by laying a point of a pencil on any part of the cord
and following it round. Instead of approaching or receding from
the center in a continuous line, as in the case of a spiral, you
will find the pencil returning to the point from which it started.



** Substitute for Insulating Cleats [348]

In wiring up door bells, alarms and telephones as well as
experimental

[Illustration: Insulators]

work the use of common felt gun wads make a very good cleat for
the wires. They are used in the manner illustrated in the
accompanying sketch. The insulated wire is placed between two wads
and fastened with two nails or screws. If one wad on the back is
not thick enough to keep the wire away from the support, put on
two wads behind and one in front of the wire and fasten in the
same manner as described.



** Electrically Operated Indicator for a Wind Vane [348]

The accompanying photograph shows a wind vane connected with
electric wires to an instrument at considerable distance which
indicates by means of a magnetic needle the direction of the wind.
The bearings of the vane consist of the head of a wornout bicycle.
A 1/2-in. iron pipe extends from the vane and is held in place by
the clamp originally used to secure the handle bar of the bicycle.
In place of the forks is attached an eight-cylinder gas engine
timer which is slightly altered in such a manner that the brush is
at all times in contact, and when pointing between two contacts
connects them both. Nine wires run from the timer, one from each
of the eight contacts, and one, which serves as the ground wire,
is fastened to the metallic body. The timer is set at such a
position that when the vane points directly north, the brush of
the timer makes a connection in the middle of a contact. When the
timer is held in this position the brush will make connections
with each of the contacts as the vane revolves.

The indicating device which is placed in a convenient place in the
house consists of

[Illustration: The Wind Vane, Magnets and Indicator]

eight 4-ohm magnets fastened upon a l-in. board. These magnets are
placed in a 10-in. circle, 45 deg. apart and with their faces
pointing toward the center. Covering these is a thin, wood board
upon which is fastened a neatly drawn dial resembling a mariner's
compass card. This is placed over the magnets in such a manner
that there will be a magnet under each of the eight principal
points marked on the dial. Over this dial is a magnetic needle or
pointer, 6 in. long, perfectly balanced on the end of a standard
and above all is placed a cover having a glass top. The eight
wires from the timer contacts connect with the outside wires of
the eight magnets separately and the inside wires from the magnets
connect with the metal brace which holds the magnets in place. A
wire is then connected from the metal brace to a push button, two
or three cells of dry battery and to the ground wire in connection
with the timer The wires are connected in such a manner that when
the vane is pointing in a certain direction the battery will be
connected in series with the coil under that part of the dial
representing the direction in which the vane is pointing, thus
magnetizing the core of the magnet which attracts the opposite
pole of the needle toward the face of the magnet and indicating
the way the wind is blowing. The pointer end of the needle is
painted black.

If the vane points in such a direction that the timer brush
connects two contacts, two magnets will be magnetized and the
needle will point midway between the two lines represented on the
dial, thus giving 16 different directions. Around the pointer end
of the needle is wound a fine copper wire, one end of which
extends down to about 1/32 in. of the dial. This wire holds the
needle in place when the pointer end is directly over the magnet
attracting it; the magnet causing the needle to "dip" will bring
the wire in contact with the paper dial. Without this attachment,
the needle would swing a few seconds before coming to a
standstill.

The vane itself is easily constructed as can be seen in the
illustration. It should be about 6 ft. long to give the best
results. The magnets used can be purchased from any electrical
store in pairs which are called "instrument magnets." Any
automobile garage can supply the timer and an old valueless
bicycle frame is not hard to find. The cover is easily made from a
picture frame with four small boards arranged to take the place of
the picture as shown.

The outfit is valuable to a person who is situated where a vane
could not be placed so as to be seen from a window and especially
at night when it is hard to determine the direction of the wind.
By simply pressing the push button on the side of the cover, the
needle will instantly point to the part of the dial from which the
wind is blowing.
--Contributed by James L. Blackmer, Buffalo, N. Y.



** A Home-Made Floor Polisher [350]

An inexpensive floor polisher can be made as follows: Secure a
wooden box with a base 8 by 12 in. and about 6 in. high, also a
piece of new carpet, 14 by 18 in. Cut 3-in. squares out of the
four corners of the carpet and place the box squarely on it. Turn
three of the flaps of the carpet up and tack them securely to the
sides of the box. Before tacking the fourth side, fold a couple of
newspapers to the right size and shove them in between the carpet
and the bottom of the box for a cushion. Fill the box with any
handy ballast, making it heavy or light, according to who is going
to use it, and securely nail on the top of the box. The handle can
be made from an old broom handle the whole of which will be none
too long. Drive a heavy screw eye into the big end of the handle
and fasten to the polisher by a staple driven through the eye into
the center of the cover, thus making a universal joint. The size
of the box given here is the best although any size near that, if
not too high, will answer the purpose just as well. The box is
pushed or pulled over the floor and the padded side will produce a
fine polish.



** How to Make a Lady's Card-Case [350]

A card-case such as is shown here makes a very appropriate present
for any lady. To make it, secure a piece of "ooze" calf skin
leather 4-1/2 by 10-1/2 in. The one shown in the accompanying
picture was made of a rich tan ooze of light weight and was lined
with a grey-green goat skin. The design was stenciled and the open
parts backed with a green silk plush having a rather heavy nap.
The lining of goat skin need not cover more than the central
part-not the flies. A piece 4-1/2 by 5

[Illustration: Design for the Cover of Lady's Card-Case]

in. will be sufficient. A piece of plush 1-1/4 by 6 in. will be
enough for the two sides. Begin work by shaping the larger piece
of leather as shown in the drawing. Allow a little margin at the
top and bottom, however, to permit trimming the edges slightly
after the parts have been sewed together. A knife or a pair of
scissors will do to cut the leather with, though a special knife,
called a chip carving knife, is most satisfactory.

The next thing is to put in the marks for the outline of the
designs and the borders. A tool having a point shaped as in the
illustration is commonly used. It is called a modeling tool for
leather and may be purchased, or, one can be made from an ordinary
nut pick by taking off the sharpness with fine emery paper so that
it will not cut the leather. To work these outlines, first moisten
the leather on the back with as much water as it will take and
still not show through on the face side. Place the leather on some
level, nonabsorbent surface and with the tool--and a straightedge
on the straight lines--indent the leather as shown. The easiest
way is to place the paper pattern on the leather and mark on the
paper. The indentations will be transferred without the necessity
of putting any lines on the leather.

With the knife cut out the stencils as shown. Paste the silk plush
to the inner side, being careful not to get any of the paste so
far out that it will show. A good leather paste will be required.

[Illustration: Leather Tools]

Next place the lining, fold the flies along the lines indicated in
the drawing. Hold the parts together and stitch them on a
sewing-machine. An ordinary sewing-machine will do if a good stout
needle is used. A silk thread that will match the leather should
be used. Keep the ooze side of the lining

[Illustration: Complete Card Case]

out so that it will show, rather than the smooth side. With the
knife and straightedge trim off the surplus material at the top
and bottom and the book is ready for use.



** Home-Made Fire Extinguisher [351]

Dissolve 20 lb. of common salt and 10 lb. of sal ammoniac in 7
gal. of water, and put the solution in thin glass bottles, cork
tightly and seal to prevent evaporation. The bottles should hold
about 1 qt. If a fire breaks out, throw one of the bottles in or
near the flames, or break off the neck and scatter the contents on
the fire. It may be necessary to use several bottles to quench the
flames.



** Crutch Made of an Old Broom [352]

An emergency crutch made of a worn-out broom is an excellent
substitute for a wood crutch, especially when one or more crutches
are needed for a short time, as in cases of a sprained ankle,
temporary lameness, or a hip that has been wrenched.

Shorten and hollow out the brush of the broom and then pad the
hollow part with cotton batting, covering it with a piece of cloth
sewed in place. Such a crutch does not heat the arm pit and there
is an elasticity about it not to be had in the wooden crutch. The
crutch can be made to fit either child or adult and owing to its
cheapness, can be thrown away when no longer needed. --Contributed
by Katharine D. Morse, Syracuse, N. Y.

[Illustration: Crutch]



** Toy Darts and Parachutes [352]

A dart (Fig. 1) is made of a cork having a tin cap, a needle and
some feathers. The needle is run through the center of the cork A
and a pin or piece of steel is put through the eye of the needle.
Take a quantity of small

[Illustration: Dart Parts and Paper Parachute]

feathers, B, and tie them together securely at the bottom. Bore a
hole in the center of the cap C, and fasten the feathers inside of
it. Fasten the cap on the cork and the dart is ready for use. When
throwing the dart at a target stand from 6 to 10 ft. away from it.

The parachute is made by cutting a piece of paper 15 in. square
and tying a piece of string to each corner. The strings should be
about 15 in. long. Tie all four strings together in a knot at the
end and fasten them in the top of a cork with a small tack. It is
best to be as high as possible when flying the parachute as the
air currents will sail it high and fast. Take hold of the
parachute by the cork and run it through the air with the wind,
letting it go at arm's length.
--Contributed by J. Gordon Dempsey, Paterson, N.J.



** A Tool for Lifting Can Covers [352]

A handy tool for prying up varnish paint, syrup and similar can
covers car be made from an old fork filed down

[Illustration: Made of an Old Fork]

to the shape shown in the illustration. The end is filed to an
edge, but not sharp.
--Contributed by Ben Grebin, Ashland, Wis.



** Keeping Rats from a Chicken Coop [352]

After trying for months to keep the rats from tunneling their way
into my chicken coop by filling in the holes, laying poisoned meat
and meal, setting traps, etc., I devised a simple and effective
method to prevent them from doing harm.

My roosting coop is 5 by 15 ft. There is a 1-in. board all around
the bottom on the inside. I used wire mesh having 1/2-in. openings
and formed it into the shape of a large tray with edges 6 in.
high, the corners being wired, and tacked it to the boards. This
not only keeps the rats out, but prevents the chickens from
digging holes, thus helping the rats to enter.
--Contributed by John A. Hellwig, Albany, N. Y.



** Homemade Telephone Receiver [353]

The receiver illustrated herewith is to be used in connection with
the transmitter described elsewhere in this volume. The body of
the receiver, A, is made of a large wooden ribbon spool. One end
is removed entirely, the other sawed in two on the line C and a
flange, F, is cut on the wood, 1/8 in. wide and 1/16 in. deep. A
flange the same size is made on the end D that was sawed off, and
the outside part tapered toward the hole as shown. The magnet is
made of a 30-penny nail, B, cut to the length of the spool, and a
coil of wire, E, wound on the head end. The coil is 1 in. long,
made up of four layers of No. 22 gauge copper magnet wire,
allowing the ends to extend out about 6 in. The nail with the coil
is then put into the hole of the spool as shown. The diaphragm C,
which is the essential part of the instrument, should be made as
carefully as possible from ferrotype tin, commonly called tintype
tin. The diaphragm is placed between the flanges on the spool and
the end D that was sawed off. The end piece and diaphragm are both
fastened to the spool with two or three slender wood screws, as
shown.

A small wooden or fiber end, G, is fitted with two binding posts
which are connected to the ends of the wire left projecting from
the magnet winding. The binding posts are attached to the line and
a trial given. The proper distance must be found between the
diaphragm and the head of the nail. This can be accomplished by
moving

[Illustration: Receiver]

the nail and magnet in the hole of the spool. When the distance to
produce the right sound is found, the nail and magnet can be made
fast by filling the open space with melted sealing wax. The end G
is now fastened to the end of the spool, and the receiver is ready
for use.



** How to Clean Jewelry [353]

To cleanse articles of silver, gold, bronze and brass use a
saturated solution of cyanide of potassium. To clean small
articles, dip each one into the solution and rinse immediately in
hot water; then dry and polish with a linen cloth. Larger articles
are cleaned by rubbing the surface with a small tuft of cotton
saturated in the solution. As cyanide of potassium is a deadly
poison, care must be taken not to have it touch any sore spot on
the flesh.



** Ornamental Iron Flower Stand [353]

The illustration shows an ornamental iron stand constructed to
hold a glass or china vase. This stand can be made by first
drawing an outline of the vase on a heavy piece of paper. The vase
is to have three supports. The shape of the scrolls forming each
support should be drawn on the paper

[Illustration: The Stand with Vase]

around the shape of the vase. A single line will be sufficient,
but care must be taken to get the shapes of the scrolls true. Take
a piece of string or, better still, a piece of small wire, and
pass it around the scroll shape on the paper. This will give the
exact length of the iron required to make the scroll. As sheet
metal is used for making the scrolls, it can be cut in the right
lengths with a pair of tinner's shears. Take a pair of round-nose
pliers, begin with the smallest scrolls, and bend each strip in
shape, using the flat-nose pliers when necessary to keep the iron
straight, placing it on the sketch from time to time to see that
the scrolls are kept to the shape required. The scrolls are
riveted and bolted together. The supports are fastened together
with rings of strip iron 3/8 in. wide, to which the supports are
fastened with rivets. The metal can be covered with any desired
color of enamel paint.



** How to Make a Coin Purse [354]

The dimensions for a leather coin purse are as follows: from A to
B, as shown in the sketch, 6-3/8 in.; from C to D, 4-1/4 in.; from
E to F, 3-1/2 in. and

[Illustration: Leather Design for a Purse]

from G to H, 3-1/4 in. Russian calf modeling leather is the
material used. A shade of brown is best as it does not soil
easily, and does not require coloring.

Cut out the leather to the size of the pattern, then moisten the
surface on the rough side with a sponge soaked in water. Be
careful not to moisten the leather too much or the water will go
through to the smooth side. Have the design drawn or traced on the
pattern. Then lay the pattern on the smooth side of the leather
and trace over the design with the small end of the leather tool
or a hard, sharp pencil. Trace also the line around the purse.
Dampen the leather as often as is necessary to keep it properly
moistened.

After taking off the pattern, retrace the design directly on the
leather to make it more distinct, using a duller point of the
tool. Press or model down the leather all around the design,
making it as smooth as possible with the round side of the tool.
Work down the outside line of the design, thus raising it.

Fold the leather on the line EF. Cut another piece of leather the
size of the side ECBD of the purse, and after putting the wrong
sides of the leather together, stitch around the edge as
designated by the letters above mentioned. Do not make this piece
come quite up to the line EF, so that the coins may be more easily
put in and taken out. About 1 in. from the lines EF on the piece,
stitch in a strip of leather about 1/4 in. wide when stitching up
the purse, through which to slip the fly AGH.



** Window Anti-Frost Solution [354]

A window glass may be kept from frosting by rubbing over the inner
surface a solution of 55 parts of glycerine and 1,000 parts of 60
per cent alcohol. The odor may be improved by adding a little oil
of amber. This solution will also prevent a glass from sweating in
warm weather.



** How to Make a Turbine Engine [355]

In the following article is described a machine which anyone can
make, and which will be very interesting, as well as useful. It
can be made without the use of a lathe, or other tools usually out
of reach of the amateur mechanic. It is neat and efficient, and a
model for speed and power. Babbitt metal is the material used in
its construction, being cast in wooden molds. The casing for the
wheel is cast in halves--a fact which must be kept in mind.

First, procure a planed pine board 1 by 12 in. by 12 ft. long. Cut
off six

[Illustration: Fig. 2]

pieces 12 in. square, and, with a compass saw, cut out one piece
as shown in Fig. 1, following the dotted lines, leaving the lug a,
and the projections B and b to be cut out with a pocket knife.
Make the lug 1/4 in. deep, and the projections B, b, 1/2 in. deep.
The entire cut should be slightly beveled.

Now take another piece of wood, and cut out a wheel, as shown in
Fig. 2. This also should be slightly beveled. When it is finished,
place it on one of the square pieces of wood, with the largest
side down, then place the square piece out of which Fig. 1 was
cut, around the wheel, with the open side down. (We shall call
that side of a mold out of which a casting is drawn, the "open"
side.) Place it so that it is even at the edge with the under
square piece and place the wheel so that the space between the
wheel and

[Illustration: Fig. 1]

the other piece of wood is an even 1/8 in. all the way around.
Then nail the wheel down firmly, and tack the other piece
slightly.

Procure a thin board 1/4 in. thick, and cut it out as shown in
Fig. 3; then nail it, with pins or small nails, on the center of
one of the square pieces of wood. Fit this to the two pieces just
finished, with the thin wheel down--but first boring a 3/4-in.
hole 1/4 in. deep, in the center of it; and boring a 3/8-in.

[Illustration: Fig. 3]

hole entirely through at the same place. Now put mold No.1 (for
that is what we shall call this mold) in a vise, and bore six
1/4-in. holes through it. Be careful to keep these holes well out
in the solid part, as shown by the black dots in Fig. 1. Take the
mold apart, and clean all the shavings out of it; then bolt it
together, and lay it away to dry.

[Illustration: Fig. 4]

Now take another of the 12-in. square pieces of wood, and cut it
out as shown in Fig. 4, slightly beveled. After it is finished,
place it between two of the 12-in. square pieces of wood, one of
which should have a 3/8-in. hole bored through its center. Then
bolt together with six 1/4-in. bolts, as shown by the

[Illustration: Fig. 5]

black dots in Fig. 4, and lay it away to dry. This is mold No.2.
Now take mold No.1; see that the bolts are all tight; lay it on a
level place, and pour babbitt metal into it, until it is full. Let
it stand for half an hour, then loosen the bolts and remove the
casting.

Now cut out one of the 12-in.-square pieces of wood as shown in
Fig. 5. This is the same as Fig. 1, only the one is left-handed,
the other right-handed. Put this together in mold No.1, instead of
the right-handed piece; and run in babbitt metal again. The
casting thus made will face together with the casting previously
made.

Pour metal into mold No.2. This will cast a paddle-wheel, which is
intended to turn inside of the casting already made.

If there should happen to be any

[Illustration: Fig. 6]

holes or spots, where the casting did not fill out, fill them by
placing a small piece of wood with a hole in it, over the
defective part, and pouring metal in to fill it up.

If you cannot obtain the use of a drill press, take an ordinary
brace, fasten a 3/8-in. drill in it, and bore a hole through the
end of a strip about 2 in. wide and 16 in. long; put the top of
the brace through this hole, and fasten the other end of the strip
to a bench, as shown in illustration. Find the center of the
paddle-wheel, place it under the drill, true it up with a square;
and drill it entirely through. Find the centers of the insides of
the other two castings, and drill them in the same manner.

A piece of mild steel 5 in. long, and 3/8-in. in diameter must now
be obtained. This is for a shaft. Commencing 1-1/2 in. from the
one end, file the shaft off flat for a distance of 1 in. Then cut
a slot in the paddle-wheel, and place the shaft inside of the
paddlewheel, with the flat part of the shaft turned to face the
slot in the wheel. Pour metal into the slot to key the wheel on to
the shaft.

The paddle-wheel is now ready to be fitted inside of the casing.
It may be necessary to file some of the ends off the paddles, in
order to let the paddle-wheel go into the casing. After it is
fitted in, so that it will turn easily, place the entire machine
in a vise, and bore three 1/4-in. holes, one in the lug, one in
the projections, B, b, and the other in the base, as shown by the
black dots in Fig. 6. Also bore the port-hole in projection B, and
the exhaust hole in projection b, and two 1/4-in. holes at d, d,
Fig. 6. Cut out a piece of gasket and fit it between the two
castings. Then bolt the castings together, screw down, and connect
to the boiler.

[Illustration: Using the Brace]

The reader must either cast a pulley out of babbitt metal, or else
go to a machinist and get a collar turned, with a boss and a set
screw, and with three small screw holes around the edge. Cut out a
small wood wheel and screw the collar fast to it, fasten it to the
shaft of the turbine and turn on the steam. Then take a knife or a
chisel, and, while it is running at full speed, turn the wheel to
the shape desired.

Your turbine engine is now ready for work, and if instructions
have been carefully followed, will do good service.



** Painting A Car [357]

When painting the automobile body and chassis be sure to stuff the
oil holes with felt or waste before applying the paint. If this
caution is not observed the holes will become clogged with paint
which will prevent any oil reaching the bearing.



** How To Build An Ice Boat [357]

The ice boat is each year becoming more popular. Anyone with even
small experience in using tools can

[Illustration: A Four-Runner Ice Yacht]

construct such a craft, and the pleasure many times repays the
effort.

Take two pieces of wood 2 by 6 in., one 6 ft. and the other 8 ft.
long. At each end of the 6-ft. piece and at right angles to it,
bolt a piece of hardwood 2 by 4 by 12 in. Round off the lower edge
of each piece to fit an old skate. Have a blacksmith bore holes
through the top of the skates and screw one of them to each of the
pieces of hardwood.

[Illustration: Plan of Ice Boat]

These skates must be exactly parallel or there will be trouble the
first time the craft is used.

Over the middle of the 6-ft. piece and at right angles to it, bolt
the 8-ft. plank, leaving 1 ft. projecting as in Fig. 1.

The rudder skate is fastened to a piece of hardwood 2 by 2 by 12
in. as the runners were fastened. This piece should be mortised 3
by 3 by 4 in. in the top before the skate is put on. Figure 2
shows the rudder post.

A piece of hardwood 1 by 6 by 6 in.

[Illustration: Details of Ice Boat Construction]

should be screwed to the under side of the 8-ft. plank at the end
with the grain running crosswise. Through this bore a hole
1-1/2-in. in diameter in order that the rudder post may fit
nicely. The tiller, Fig. 3, should be of hardwood, and about 8 in.
long.

To the under side of the 8-ft. plank bolt a piece of timber 2 by 4
by 22 in. in front of the rudder block, and to this cross piece
and the 6-ft. plank nail 8-in. boards to make the platform.

The spar should be 9 ft. long and 2-1/2 in. in diameter at the
base, tapering to 1-1/2 in. at the top. This fits in the square
hole, Fig. 1. The horn should be 5-1/2 ft. long, 2 by 3 in. at the
butt and 1 in. at the end.

Figure 4 gives the shape and dimensions of the mainsail which can
be made of muslin. Run the seam on a machine, put a stout cord in
the hem and make loops at the corners.

Figure 6 shows the way of rigging the gaff to the spar. Figure 7
shows the method of crotching the main boom and Fig. 8 a reef
point knot, which may come in handy in heavy winds.

Make your runners as long as possible, and if a blacksmith will
make an iron or steel runner for you, so much the better will be
your boat.



** Electric Rat Exterminator [358]

Some time ago we were troubled by numerous large rats around the
shop, particularly in a storehouse about 100 ft. distant, where
they often did considerable damage. One of the boys thought he
would try a plan of electrical extermination, and in order to
carry out his plan he picked up an old zinc floor plate that had
been used under a stove and mounted a wooden disk 6 in. in
diameter in the center. On this disk he placed a small tin pan
about 6 in. in diameter, being careful that none of the fastening
nails made an electrical connection between the zinc plate and the
tin pan.

This apparatus was placed on the floor of the warehouse where it
was plainly visible from a window in the shop where we worked and
a wire was run from the pan and another from the zinc plate
through the intervening yard and into the shop. A good sized
induction coil was through connected with these wires and about
six dry batteries were used to run the induction coil whenever a
push button was manipulated.

It is quite evident that when a rat put its two fore feet on the
edge of the pan in order to eat the mush which it contained, that
an electrical connection would be made through the body of the
rat, and when we pushed the button up in the shop the rat would be
thrown

[Illustration: Electric Rat Trap]

2 or 3 ft. in the air and let out a terrific squeak. The
arrangement proved quite too effective, for after a week the rats
all departed and the boys all regretted that their fun was at an
end.
--Contributed by John D. Adams, Phoenix, Ariz.



** How to Make a Simple Fire Alarm [359]

A fire alarm which is both inexpensive and simple in construction
is shown in the illustration. Its parts are as follows:

A, small piece of wood; B, block of wood nailed to A; S S. two
pieces of sheet brass about 1/4 in. wide, bent into a hook at each
end; P, P, binding-posts fastening the springs S S, to block B, so
that they come in contact at C. W is a piece of wax crayon just
long enough to break the contact at C when inserted as shown in
the illustration.

When these parts have been put together in the manner described,
connect the device in circuit with an electric bell, and place it
behind a stove.

[Illustration: Simple Fire Alarm]

When the stove becomes too hot the wax will melt at the ends,
allowing the springs to contact at C, and the alarm bell will
ring.
--Contributed by J. R. Comstock, Mechanicsburg, Pa.



** To Build a Merry-Go-Round [359]

This is a very simple device, but one that will afford any amount
of amusement. The center post rests in an auger hole bored in an
old stump or in a post set in the ground. The stump makes the best
support. The center pole should be 10 ft. high. An old wheel is
mounted at the top of the pole, and the pole works in the wheel as
an axle, says the American Boy. The wheel is anchored out by
several guy

[Illustration: Home-Made Merry-Go-Round]

wires. The seat arms may be any length desired. A passenger rides
in each seat and the motorman takes his station at the middle.



** Arbor Wheels [359]

Emery wheel arbors should be fitted with flanges or washers having
a slight concave to their face.



** Novelty Clock for the Kitchen [360]

An inexpensive and easy way to make an unique ornament of a clock

[Illustration: The Clock with Holder]

for kitchen use is to take an old alarm clock or a new one if
preferred, and make it into a clock to hang on the wall. Take the
glass, dial and works out of the shell and cut some pieces out of
the metal so that when the pieces left are turned back it will
have the appearance as in Fig. 1. Then get a 10-cent frying pan, 6
in. in diameter, and drill a hole in the center so the shaft for
the hands will easily pass through and extend out far enough to
replace the two hands. Put the works back in the metal shell and
solder it to the frying pan by the pieces turned out as in Fig. 2.
Gild the pan all over, including the handle, and print black
figures in the small circles. Calendar figures can be pasted on
small circles and these pasted on the frying pan. The parts can be
divided into minutes with small lines the same as shown in the
drawing. Make new hands that are long enough to reach the figures
from sheet brass or tin and paint them black.
--Contributed by Carl P. Herd, Davenport, Iowa



** How to Make a Small Silver Plating Outfit [360]

Take an ordinary glass fruit jar or any other receptacle in glass,
not metal, which will hold 1 qt. of liquid and fill it with rain
or distilled water and then add 3/4 oz. of silver chloride and
1-1/2 oz. of c.p. potassium cyanide. Let this dissolve and
incorporate well with the water before using. Take an ordinary wet
battery and fasten two copper wires to the terminals and fasten
the other ends of the wires to two pieces of heavy copper wire or
1/4-in. brass pipe. The wires must be well soldered to the brass
pipe to make a good connection. When the solution is made up and
entirely dissolved the outfit is ready for plating.

Procure a small piece of silver, a silver button, ring, chain or
anything made entirely of silver and fasten a small copper wire to
it and hang on the brass pipe with connections to the carbon of
the battery. Clean the article to be plated well with pumice and a
brush saturated in water. When cleaning any article there should
be a copper wire attached to it. Do not touch the article after
you once start to clean it, or the places touched by your fingers
will cause the silver plate to peel off when finished. When well
scoured, run clear, cold water over the article and if it appears
greasy, place in hot water. When well cleaned place in the plating
bath and carefully watch the results. If small bubbles come to the
surface you will know that you have too much of the anode or the
piece of silver hanging in the solution and you

[Illustration: Plating Jar and Battery]

must draw out enough of the piece until you can see no more
bubbles. Leave the piece to be plated in the solution for about
one-half hour, then take the article out and with a tooth brush
and some pumice, clean the yellowish scum off, rinse in clear
water and dry in sawdust. When thoroughly dry, take a cotton
flannel rag and some polishing powder and polish the article. The
article must have a fine polish before plating if it is desired to
have a finely polished surface after the plate is put on.

In order to see if your battery is working, take a small copper
wire and touch one end to the anode pipe and the other end to the
pipe holding the article to be plated. When these two parts touch
there will be a small spark. Always take the zincs out of the
solution when not in use and the batteries will last longer. This
description applies only to silver plating. Articles of lead,
pewter, tin or any soft metal cannot be silver plated unless the
article is first copper plated.



** Removing a Tight-Fitting Ring from a Finger [361]

When a ring cannot be removed easily from the finger, take a
string or thread and draw one end through between the ring and the
flesh. Coil the other end of the string around the finger covering
the part from the ring to and over the finger joint. Uncoil the
string by taking the end placed through the ring and at the same
time keep the ring close up to the string. In this way the ring
can be easily

[Illustration: Wrapping the Finger]

slipped over the knuckle and off from the finger.
--Contributed by J. K. Miller, Matietta, Penn.



** A Photographic Jig-Saw Puzzle [361]

Take any photographic print and mount it on heavy cardboard, or,
if you

[Illustration: Picture Marked for Cutting]

have a jig saw, a thin smooth wood board and mark out various
shaped pieces as shown in the accompanying cut. If the picture is
mounted on cardboard, the lines can be cut through with a sharp
pointed knife. If you have a jig saw, you can make a bromide
enlargement from the negative you have selected and mount the
print on a smooth board that is not too thick. This wood-mounted
picture can be sawed out making all shapes of blocks, which forms
a perfect jig-saw puzzle.
--Contributed by Erich Lehmann, New York City.



** Rolling Uphill Illusion [361]

This interesting as well as entertaining illusion, can be made by
anyone having a wood-turning lathe. A solid, similar to two cones
placed base to base, is accurately turned in a lathe, the sides
sloping to an angle of 45 deg. The spindle can be turned out of
the solid at the same time as the cone; or, after turning the
cone, drive an iron or wood shaft through the center making a
tight fit.

The boards for the track are made with a sloping edge on which the
cone is to roll. This slope will depend on the diameter of the
cone, which can be any size from 3 to 12 in. The slope should not
be too flat, or the cone will not roll, and it should be such that
the

[Illustration: The Illusion]

one end will be higher than the other by a little less than half
the diameter of the cone. Thus it will be seen that the diameter
of the cone determines the length of the slope of the tracks. A
notch should be cut in the tracks, as indicated, for the shaft to
drop into at the end of the course.

The lower end of the tracks are closed until the high edge of the
cone rests upon the inside edges of the tracks and the high end
spread sufficiently to take the full width of the cone and to
allow the shaft to fall into the notches. When the cone and tracks
are viewed from the broadside the deception will be more perfect,
and will not be discovered until the construction of the model is
seen from all sides. Should it be difficult to make the cone from
wood, a good substitute can be made from two funnels.
--Contributed by I. G. Bayley, Cape May Point, N.J.



** Annealing Chisel Steel [362]

Persons who have occasion to use tool or carbon steel now and then
and do not have access to an assorted stock of this material find
that the kind most readily obtained at the hardware store is the
unannealed steel known as chisel steel. Machining or filing such
steel is exceedingly slow and difficult, besides the destruction
of tools; as a matter of fact this steel is intended for chisels,
drills, and like tools which require only forging and filing. If
this steel is annealed, it can be worked as easily as the more
expensive annealed steel.

Annealing may be done by heating the steel to a cherry red, not
any more, and burying it in a box of slaked lime, where it is
allowed to remain until all the heat is gone. If well done, the
metal will be comparatively soft and in a condition to machine
easily and rapidly. In lieu of lime, bury in ashes, sand, loam, or
any substance not inflammable, but fine enough to closely surround
the steel and exclude the air so that the steel cools very slowly.

If possible, keep the steel red hot in the fire several hours, the
longer the better. In certain processes, like that of file
manufacturing, the steel blanks are kept hot for 48 hours or more.
Where it is impossible to wait so long as the foregoing method
takes, then a cold water anneal may be used with less time. This
method consists of heating the work as slowly and thoroughly as
the time will permit, then removing the steel from the fire and
allowing it to cool in the air until black and then quenching in
water.

In addition to softening the steel, annealing benefits the metal
by relieving strains in the piece. Should a particularly accurate
job be called for, the steel should be annealed again after the
roughing cuts have been taken and before machining to the final
size. This will insure a true job and diminishes the danger of
spring in the final hardening.
--Contributed by Donald A. Hampson, Middletown, N. Y.

          *     *     *     *     *

[Illustration: The above photograph was made by first printing a
maple leaf of the paper, not too dark, then printing on top the
picture from the negative, and finishing in the usual way.]




** How to Make a Post Card Holder [363]

This holder is designed to lay flat on the counter or to stack one
on top of the other, keeping each variety of cards separate, or a
number of them can be fastened on any upright surface to display
either horizontal or vertical cards.

The holders can be made from sheet tin, zinc, brass or aluminum.
The dimensions for the right size are given in Fig. 1; the dotted
line showing where the bends are made. The

[Illustration: Pattern for Cutting the Metal]

completed holder is shown in Fig. 2 as fastened to a wall.
--Contributed by John F. Williamson, Daytona, Fla.



** Unused Paint [363]

Do not allow paint that is left over from a job to stand
uncovered. The can should be tightly sealed and the paint will be
found suitable for use for several days.



** Perfume-Making Outfit [363]

The real perfume from the flowers is not always contained in the
liquid purchased for perfume. The most expensive perfume can be
made at home for less than 10 cents an ounce. The outfit necessary
is a large bottle or glass jar with a smaller bottle to fit snugly
into the open mouth of the large one. Secure a small piece of very
fine sponge and wash it clean to thoroughly remove all grit and
sand.

[Illustration: Bottle with Flowers]

Saturate the sponge with pure olive oil, do not use strong oil,
and place it inside of the smaller bottle.

Fill the large bottle or jar with flowers, such as roses,
carnations, pansies, honeysuckles or any flower having a strong
and sweet odor. Place the small bottle containing the sponge
upside down in the large one, as shown in the illustration.

The bottle is now placed in the sun and kept there for a day and
then the flowers are removed and fresh ones put in. Change the
flowers each day as long as they bloom. Remove the sponge and
squeeze out the oil. For each drop of oil add 2 oz. of grain
alcohol. If stronger perfume is desired add only 1 oz. alcohol to
each drop of oil.



** Home-Made Duplicator for Box Cameras [363]

The projecting tube of the lens on a hand camera can be easily
fitted with a duplicator while the box camera with its lens set on
the inside and nothing but a hole in the box does not have such
advantages. A small piece of heavy cardboard can be made to
produce the same results on a box camera as a first-class
duplicator applied to a hand camera.

[Illustration: Duplicator Attached to a Camera]

The cardboard is cut triangular and attached to the front end of
the camera as shown in Fig. 1 with a pin about 1 in. above the
lens opening. A rubber band placed around the lower end of the
cardboard and camera holds the former at any position it is
placed. A slight pressure of the finger on the point A, Fig. 2,
will push the cardboard over and expose one-half of the plate and
the same pressure at B, Fig. 3, will reverse the operation and
expose the other one-half. Pins can be stuck in the end of the
camera on each side of the lens opening at the right place to stop
the cardboard for the exposure. With this device one can duplicate
the picture of a person on the same negative.
--Contributed by Maurice Baudier, New Orleans, La.



** Optical Illusions [364]

The accompanying sketch shows two optical illusions, the first
having a perfect circle on the outside edge

[Illustration: The Two Illusions]

appears to be flattened at the points A, and the arcs of the
circle, B, appear to be more rounding. In the second figure the
circle appears to have an oval form with the distance from C to C
greater than from D to D. A compass applied to the circles in
either figures will show that they are perfectly round.
--Contributed by Norman S. Brown, Chippewa Falls, Wis.



** Use of Kerosene in Polishing Metals [364]

Anyone who has polished a flat iron or steel surface with emery
cloth knows how soon the cloth gums and fills up. The cloth in
this condition will do little or no cutting. A simple remedy for
this trouble is to use kerosene on the surface. The oil floats
away a large part of the gumming substance and leaves the emery
cloth sharp and clean to do the best work, also, it seems to act
as a lubricant to keep particles of metal from collecting on the
cloth and scratching or digging in the surface of the metal. A
very light lard oil is equally good for this purpose, but not
always easily obtained. A surface polished where oil or kerosene
is used does not rust so easily as one polished dry, for the
reason that a little oil remains on the metal.

Kerosene is the best to use on oil stones, being better than
heavier oil. This oil readily floats away all particles of the
feather edge that are liable to become loosened and forced into
the stone. These particles of metal when stuck to the stone are
the cause of spoiling it, as well as nicking the tools that are
being sharpened. Keep the surface of the stone well oiled at all
times to make the cutting free.
--Contributed by Donald A. Hampson, Middletown, N. Y.



** How to Make Lamps Burn Brightly [364]

For a good, steady light there is nothing better than a lamp, but
like most everything it must have attention. After cleaning well
and fitting it, place a small lump of camphor in the oil vessel.
This will greatly improve the light and make the flame clearer and
brighter. If there is no camphor at hand add a few drops of
vinegar occasionally.



** A Practical Camera for Fifty Cents [365]
By C. H. Claudy

I say for fifty cents, but really this is an outside estimate. If
you possess a few tools and the rudiments of a shop, by which is
meant a few odds and ends of screws, brass and nails, you can
really make this camera for nothing.

The camera box is the first consideration, and for this a cigar
box answers every purpose. It is better to use one of the long
boxes which contain a hundred cigars and which have square ends.
This box should be cut down, by means of a saw and a plate, until
the ends are 4 in. square. Leave the lid hinged as it is when it
comes. Clean all the paper from the outside and inside

[Illustration: Construction of Camera Box]

of the box--which may be readily done with a piece of glass for a
scraper and a damp cloth--and paint the interior of the box a dead
black, either with carriage makers' black or black ink.

Now bore in the center of one end a small hole, 1/4 in. or less in
diameter. Finally insert on the inside of the box, on the sides,
two small strips of wood, 1/8 by 1/4 in. and fasten them with
glue, 1/8 in. from the other end of the box. Examine Fig. 1, and
see the location of these strips, which are lettered EE. Their
purpose is to hold the plate, which may be any size desired up to
4 in. square. Commercially, plates come 3-1/2 by 3-1/2 in., or, in
the lantern slide plate, 3-1/4 by 4 in. If it is desired to use
the 3-1/2 by 3-1/2 in. plates. which is advised, the box should
measure that size in its internal dimensions.

We now come to the construction of the most essential part of the
camera--the pin hole and the shutter, which take the place of the
lens and shutter used in more expensive outfits. This construction
is illustrated in Fig. 4. Take a piece of brass, about 1/16-in.
thick and 1-1/2 in. square. Bore a hole in each corner, to take a
small screw, which will fasten it to the front of the camera. With
1/4-in. drill bore nearly through the plate in the center, but be
careful that the point of the drill does not come through. This
will produce the recess shown in the first section in Fig. 4. Now
take a No. 10 needle, insert the eye end in a piece of wood and
very carefully and gently twirl it in the center of the brass
where it is the thinnest, until it goes through. This pin hole, as
it is called, is what produces the image on the sensitive plate,
in a manner which I shall presently describe. The shutter consists
of a little swinging piece of brass completely covering the recess
and pin hole, and provided with a little knob at its lower end.
See Fig. 3, in which F is the front of the camera, B the brass
plate and C the shutter. This is also illustrated in the second
cross section in Fig. 4. In the latter I have depicted it as swung
from a pivot in the brass, and in Fig. 3 as hung from a screw in
the wood of the front board; either construction will be
effective.

Lastly, it is necessary to provide a finder for this camera in
order to know what picture you are taking. Make a little frame of
wire, the size of the plate you are using, and mount it upright
(see Fig. 5) on top of the camera as close to the end where the
pin hole is as you can. At the other end, in the center, erect a
little pole of wire half the height of the plate. If now you look
along the top of this little pole, through the wire frame and see
that the top of the little pole appears in the center of the
frame, everything that you see beyond will be

[Illustration: Pin Hole and Shutter Construction]

taken on the plate, as will be made plain by looking at the dotted
lines in Fig. 5, which represents the outer limits of your vision
when confined within the little frame.

[Illustration: Explanation of Action of Pin Hole]

When you want to use this camera, take it into an absolutely dark
room

[Illustration: Constructing a Finder for Camera]

and insert a plate (which you can buy at any supply store for
photographers) in the end where the slides of wood are, and
between them and the back of the box. Close the lid and secure it
with a couple of rubber bands. See that the little shutter covers
the hole. Now take the camera to where you wish to take a
photograph, and rest it securely on some solid surface. The
exposure will be, in bright sunlight and supposing that your
camera is 10 in. long, about six to eight seconds. This exposure
is made by lifting the little brass shutter until the hole is
uncovered, keeping it up the required time, and then letting it
drop back into place. It is important that the camera be held
rigid during the exposure, and that it does not move and is not
jarred--otherwise the picture will be blurred. Remove the plate in
the dark room and pack it carefully in a pasteboard box and
several wrappings of paper to protect it absolutely from the
light. It is now ready to be carried to some one who knows how to
do developing and printing.

To explain the action of the pin hole I would direct attention to
Fig. 2. Here F represents the front of the camera, D the pinhole,
AA the plate and the letters RR, rays from a lighted candle. These
rays of course, radiate in all directions, an infinite multitude
of them. Similar rays radiate from every point of the object, from
light reflected from these points. Certain of these rays strike
the pin hole in the front of the camera, represented here by RRRR.
These rays pass through the pin hole, and as light travels only in
straight lines, reach the plate AA, forming an inverted image of
the object, in this case a candle in a candlestick. Millions of
rays are given off by every point in every object which is lighted
by either direct or reflected light. To all practical purposes
only one of these rays from each point in an object can pass
through a minute opening like a pin hole. This being so, any
screen which interrupts these selected rays of light will show
upon it a picture of the object, only inverted. If that screen
happens to be a photographically sensitive plate, which is
protected from all other light by being in a dark box, upon it
will be imprinted a photographic image which can be made visible
by the application of certain chemicals, when it becomes a
negative, from which may be printed positives. This camera is not
a theoretical possibility, but an actual fact. I have made and
used one successfully, as a demonstration of pin-hole photography.



** Use for an Old Clock [367]

Remove the hair spring of the clock, and fasten a spring to one
end of the pawl and a small wire to the other end. Make a slit in
the case of the clock opposite the pawl. Fasten the spring on the
outside in any convenient way and pass the wire through the slit
to an eccentric or other oscillating body. To make the dial, paste
a piece of paper over the old dial, pull the wire back and forth
one hundred times, and make a mark where the minute hand stops.
Using this for a unit divide up the whole dial. The hour hand has
an inner circle of its own. Put the alarm hand at a little before
twelve and wind the alarm. When the alarm is

[Illustration: Revolution Recorder]

unwound the hour hand starts on a new trip. The clock I used was
put on an amateur windmill and when the hour hand went around once
86,400 revolutions or jerks on the wire were made, while the
minute hand recorded one-twelfth of this number, or 7,200.
--Contributed by Richard H. Ranger, Indianapolis, Ind.



** Renewing Dry Batteries [367]

Dry batteries, if not too far gone, can be renewed by simply
boring a small hole through the composition on top of each carbon
and pouring some strong salt water or sal ammoniac solution into
the holes. This kink is sent us by a reader who says that the
process will make the battery nearly as good as new if it is not
too far gone beforehand.



** Saving a Brush [367]

If a round brush spreads too much, slip a rubber band over the
upper part of the bristles.



** How to Make a Simple Burglar Alarm [368]

Take a piece of any wood about 6 by 8 in. for the base. This may
be finished in any way desired. For the contact points use brass
or any sheet metal

[Illustration: Simple Burglar Alarm]

which will be satisfactory. Take a piece about 2-1/2 or 3 in. in
length and bend the ends up about 1/2 in. in a vertical position
as shown. Fasten this to the top of the board using screws or
nails. Under this strip of metal fasten a copper wire which can be
connected to a binding-post on the board if desired. Take another
piece of metal about 4-1/2 in. in length and make a lever of it in
the shape shown in the diagram. Fasten this so that one end of it
will swing freely, but not loosely between the ends of the other
piece marked C-C. Near the end fasten a spiral spring, S, which
can be obtained almost anywhere. Fasten the end of this to the
screw marked X. Also fasten to this screw a copper wire leading to
the binding-post. In the lower end of the lever make a small hole
to fasten a string through.

This string may be fastened across a door or window and any
movement of it will pull it to the contact point on the right. If
the string is cut or broken the spring will pull the lever to the
contact point on the left and thus complete the circuit. If the
string is burned it will also act as a fire alarm.



** How to Fit Corks [368]

Occasionally odd-sized bottles are received in stores which
require corks cut to fit them. No matter how sharp a knife may be,
it will leave some sharp edges after cutting the cork, which will
cause leakage. The illustration shows three very effective methods
of reducing the size of corks. The one shown in Fig. 1 is made
from two pieces of 1/2-in. wood fastened together at one end with
a common hinge. Two or three grooves are cut cross-wise in sizes
desired. The cork is put into the groove and both pieces are
pressed together, which will make the cork smaller.

Rolling the cork between two flat

[Illustration: Three Methods for Reducing Size of Corks]

surfaces (Fig. 2) is simple and almost as good as pressing in the
grooves. A cork rolled on the floor (Fig. 3) is a quick and
effective way. A slower and equally as good way is to soak the
cork in hot water for a short time.
--Contributed by L. Szerlip, Brooklyn, N. Y.



** Right Handed Engine [368]

Standing at the cylinder end and looking toward the flywheel of an
engine, the wheel will be at the right if the engine is
right-hand.



** Home-Made Crutch [369]

While a fractured bone was healing in the limb of my boy he needed
a pair of crutches and not being able to secure the right length,
I set about to make the crutches from two broom handles. I split
the handles to within 1 ft. of the end (Fig. 1) with a rip saw,
and then stuck them in a barrel of water for three days to make
the wood pliable for bending. A grip for each stick was made as
long as the hand is wide and a hole bored through the center the
size of a No. 10 gauge wire. These grips were placed between the
two halves of each stick at the right distance for the length of
the boy's arm and a wire run through both split

[Illustration: A Broom Handle Crutch]

pieces and the handle then riveted as shown in Fig. 2. Another
piece was cut as shown at A, Fig. 3, and nailed to the upper ends
of each half of the broom handle.
--Contributed by Geo. P. Grehore, Nashville, Tenn.



** Home-Made Necktie Holder [369]

The gas bracket is considered a good place to hang neckties, even
if it does crowd them together. The illustration shows a better
method, a curtain rod attached to one end of a bureau. Two
long-shanked, square-hooked screws should be used, so they may be
screwed beneath and close up to the projecting top. When removed
they will leave no

[Illustration: Hanger for Ties]

disfiguring holes.
--Contributed by C. W. Neiman, New York City.



** How to Make a Trousers Hanger [369]

Secure from your tinsmith a piece of sheet metal 7 in. wide and 12
in. long. Cut the metal as shown in Fig. 1 and make a close bend
at the point.A, but not too close to cause it to break. The piece
will then appear as shown in Fig. 2. Cut a piece from the waste
material 1/2 in. wide and 2-1/4 in. long and bend it around the
two pieces B, Fig. 2, so it will slide freely on their length.
Bend the edges C in for 1/8 in. to hold the trousers firmly. Drill
a hole through the top end of B and attach a wire formed into a
hook for use in hanging on a nail. The bottom end of the trousers
is inserted between the jaws C and the small ferrule pushed

[Illustration: Cut from Sheet Metal]

down to clamp them on the cloth.
--Contributed by A. Levinson, Saginaw, Michigan.



** Easy Designs in Ornamental Iron Work [370]

Many an industrious lad has made money manufacturing the common
forms of wood brackets, shelves, boxes, stands, etc., but the day
of the scroll

[Illustration: Fig. 1 to 6]

saw and the cigar-box wood bracket and picture frame has given way
to the more advanced and more profitable work of metal
construction. Metal brackets, stands for lamps, gates, parts of
artistic fences for gardens, supporting arms for signs, etc., are
among the articles of modern times that come under the head of
things possible to construct of iron in the back room or attic
shop. The accompanying sketches present some of the articles
possible to manufacture.

First, it is essential that a light room be available, or a
portion of the cellar where there is light, or a workshop may be
built in the yard. Buy a moderate sized anvil, a vise and a few
other tools, inclu